summaryrefslogtreecommitdiffstats
path: root/drivers/tty/serial/serial_core.c
Commit message (Collapse)AuthorAgeFilesLines
* serial: Clear UPF_DEAD before calling tty_port_register_device_attr_serdev()Hans de Goede2024-05-101-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a serdev_device_driver is already loaded for a serdev_tty_port when it gets registered by tty_port_register_device_attr_serdev() then that driver's probe() method will be called immediately. The serdev_device_driver's probe() method should then be able to call serdev_device_open() successfully, but because UPF_DEAD is still dead serdev_device_open() will fail with -ENXIO in this scenario: serdev_device_open() ctrl->ops->open() /* this callback being ttyport_open() */ tty->ops->open() /* this callback being uart_open() */ tty_port_open() port->ops->activate() /* this callback being uart_port_activate() */ Find bit UPF_DEAD is set in uport->flags and fail with errno -ENXIO. Fix this be clearing UPF_DEAD before tty_port_register_device_attr_serdev() note this only moves up the UPD_DEAD clearing a small bit, before: tty_port_register_device_attr_serdev(); mutex_unlock(&tty_port.mutex); uart_port.flags &= ~UPF_DEAD; mutex_unlock(&port_mutex); after: uart_port.flags &= ~UPF_DEAD; tty_port_register_device_attr_serdev(); mutex_unlock(&tty_port.mutex); mutex_unlock(&port_mutex); Reported-by: Weifeng Liu <weifeng.liu.z@gmail.com> Closes: https://lore.kernel.org/platform-driver-x86/20240505130800.2546640-1-weifeng.liu.z@gmail.com/ Tested-by: Weifeng Liu <weifeng.liu.z@gmail.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20240509141549.63704-1-hdegoede@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: core: Call device_set_awake_path() for console portClaudiu Beznea2024-05-041-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In case the UART port is used as a console, no_console_suspend is available in bootargs and UART port is part of a software-controlled power domain we need to call device_set_awake_path(). This lets the power domain core code know that this domain should not be powered off during system suspend. Otherwise, the UART port power domain is turned off, nothing is printed while suspending and the suspend/resume process is blocked. This was detected on the Renesas RZ/G3S SoC while adding support for power domains. Based on code investigation (on v6.9-rc5), this issue is present on other SoCs (e.g., Renesas R-Mobile A1 [1], IMX8QXP [2]) and different SoCs have particular implementation to handle it. Due to this the patch added the call of device_set_awake_path() in uart_suspend_port() instead of having it in the platform specific UART driver. [1] drivers/pmdomain/renesas/rmobile-sysc.c:116 [2] drivers/pmdomain/imx/scu-pd.c:357 Suggested-by: Ulf Hansson <ulf.hansson@linaro.org> Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Tony Lindgren <tony.lindgren@linux.intel.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Link: https://lore.kernel.org/r/20240430095930.2806067-1-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge 6.9-rc5 into tty-nextGreg Kroah-Hartman2024-04-231-4/+18
|\ | | | | | | | | | | | | | | | | We want the tty fixes in here as well, and it resolves a merge conflict in: drivers/tty/serial/serial_core.c as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * serial: core: Fix missing shutdown and startup for serial base portTony Lindgren2024-04-111-3/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We are seeing start_tx being called after port shutdown as noted by Jiri. This happens because we are missing the startup and shutdown related functions for the serial base port. Let's fix the issue by adding startup and shutdown functions for the serial base port to block tx flushing for the serial base port when the port is not in use. Fixes: 84a9582fd203 ("serial: core: Start managing serial controllers to enable runtime PM") Cc: stable <stable@kernel.org> Reported-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Tony Lindgren <tony@atomide.com> Link: https://lore.kernel.org/r/20240411055848.38190-1-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * serial: core: Clearing the circular buffer before NULLifying itAndy Shevchenko2024-04-091-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The circular buffer is NULLified in uart_tty_port_shutdown() under the spin lock. However, the PM or other timer based callbacks may still trigger after this event without knowning that buffer pointer is not valid. Since the serial code is a bit inconsistent in checking the buffer state (some rely on the head-tail positions, some on the buffer pointer), it's better to have both aligned, i.e. buffer pointer to be NULL and head-tail possitions to be the same, meaning it's empty. This will prevent asynchronous calls to dereference NULL pointer as reported recently in 8250 case: BUG: kernel NULL pointer dereference, address: 00000cf5 Workqueue: pm pm_runtime_work EIP: serial8250_tx_chars (drivers/tty/serial/8250/8250_port.c:1809) ... ? serial8250_tx_chars (drivers/tty/serial/8250/8250_port.c:1809) __start_tx (drivers/tty/serial/8250/8250_port.c:1551) serial8250_start_tx (drivers/tty/serial/8250/8250_port.c:1654) serial_port_runtime_suspend (include/linux/serial_core.h:667 drivers/tty/serial/serial_port.c:63) __rpm_callback (drivers/base/power/runtime.c:393) ? serial_port_remove (drivers/tty/serial/serial_port.c:50) rpm_suspend (drivers/base/power/runtime.c:447) The proposed change will prevent ->start_tx() to be called during suspend on shut down port. Fixes: 43066e32227e ("serial: port: Don't suspend if the port is still busy") Cc: stable <stable@kernel.org> Reported-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202404031607.2e92eebe-lkp@intel.com Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20240404150034.41648-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * serial: core: Fix regression when runtime PM is not enabledTony Lindgren2024-04-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 45a3a8ef8129 ("serial: core: Revert checks for tx runtime PM state") caused a regression for Sun Ultra 60 for the sunsab driver as reported by Nick Bowler <nbowler@draconx.ca>. We need to add back the check runtime PM enabled state for serial port controller device, I wrongly assumed earlier we could just remove it. Fixes: 45a3a8ef8129 ("serial: core: Revert checks for tx runtime PM state") Cc: stable <stable@kernel.org> Reported-by: Nick Bowler <nbowler@draconx.ca> Signed-off-by: Tony Lindgren <tony@atomide.com> Link: https://lore.kernel.org/r/20240325071649.27040-1-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | serial: core: Extract uart_alloc_xmit_buf() and uart_free_xmit_buf()Andy Shevchenko2024-04-171-44/+54
| | | | | | | | | | | | | | | | | | After conversion to the kfifo, it becomes possible to extract two helper functions for better maintenance and code deduplication. Do it here. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20240409174057.1104262-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | serial: drop debugging WARN_ON_ONCE() from uart_put_char()Jiri Slaby (SUSE)2024-04-171-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pengfei Xu reports, that the -next commit 1788cf6a91d9 (tty: serial: switch from circ_buf to kfifo) tries to emit a WARNING and that leads to lockdep errors. Obviously we cannot print anything from uart_put_char()! This WARN_ON_ONCE() was/is a debug aid to check if the condition in uart_put_char() can happen at all. Pengfei Xu confirmed it can. Unlike me and kbuild bot in my queue. Second, I completely forgot about it, so I did not remove it in the final version, nor mentioned it in the commit log. Drop it now as we are all good. And we even have stack traces (and a reproducer)! Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Reported-by: Pengfei Xu <pengfei.xu@intel.com> Link: https://lore.kernel.org/r/20240416071904.21440-1-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | serial: core: Add support for DEVNAME:0.0 style naming for kernel consoleTony Lindgren2024-04-091-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We can now add hardware based addressing for serial ports. Starting with commit 84a9582fd203 ("serial: core: Start managing serial controllers to enable runtime PM"), and all the related fixes to this commit, the serial core now knows to which serial port controller the ports are connected. The serial ports can be addressed with DEVNAME:0.0 style naming. The names are something like 00:04:0.0 for a serial port on qemu, and something like 2800000.serial:0.0 on platform device using systems like ARM64 for example. The DEVNAME is the unique serial port hardware controller device name, AKA the name for port->dev. The 0.0 are the serial core controller id and port id. Typically 0.0 are used for each controller and port instance unless the serial port hardware controller has multiple controllers or ports. Using DEVNAME:0.0 style naming actually solves two long term issues for addressing the serial ports: 1. According to Andy Shevchenko, using DEVNAME:0.0 style naming fixes an issue where depending on the BIOS settings, the kernel serial port ttyS instance number may change if HSUART is enabled 2. Device tree using architectures no longer necessarily need to specify aliases to find a specific serial port, and we can just allocate the ttyS instance numbers dynamically in whatever probe order To do this, let's match the hardware addressing style console name to the character device name used, and add a preferred console using the character device name. Note that when using console=DEVNAME:0.0 style kernel command line, the 8250 serial console gets enabled later compared to using console=ttyS naming for ISA ports. This is because the serial port DEVNAME to character device mapping is not known until the serial driver probe time. If used together with earlycon, this issue is avoided. Signed-off-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Dhruva Gole <d-gole@ti.com> Link: https://lore.kernel.org/r/20240327110021.59793-5-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | tty: serial: switch from circ_buf to kfifoJiri Slaby (SUSE)2024-04-091-35/+21
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Switch from struct circ_buf to proper kfifo. kfifo provides much better API, esp. when wrap-around of the buffer needs to be taken into account. Look at pl011_dma_tx_refill() or cpm_uart_tx_pump() changes for example. Kfifo API can also fill in scatter-gather DMA structures, so it easier for that use case too. Look at lpuart_dma_tx() for example. Note that not all drivers can be converted to that (like atmel_serial), they handle DMA specially. Note that usb-serial uses kfifo for TX for ages. omap needed a bit more care as it needs to put a char into FIFO to start the DMA transfer when OMAP_DMA_TX_KICK is set. In that case, we have to do kfifo_dma_out_prepare twice: once to find out the tx_size (to find out if it is worths to do DMA at all -- size >= 4), the second time for the actual transfer. All traces of circ_buf are removed from serial_core.h (and its struct uart_state). Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Cc: Al Cooper <alcooperx@gmail.com> Cc: Matthias Brugger <matthias.bgg@gmail.com> Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> Cc: Kumaravel Thiagarajan <kumaravel.thiagarajan@microchip.com> Cc: Tharun Kumar P <tharunkumar.pasumarthi@microchip.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Richard Genoud <richard.genoud@gmail.com> Cc: Nicolas Ferre <nicolas.ferre@microchip.com> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Claudiu Beznea <claudiu.beznea@tuxon.dev> Cc: Alexander Shiyan <shc_work@mail.ru> Cc: Baruch Siach <baruch@tkos.co.il> Cc: Maciej W. Rozycki <macro@orcam.me.uk> Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Fabio Estevam <festevam@gmail.com> Cc: Neil Armstrong <neil.armstrong@linaro.org> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Jerome Brunet <jbrunet@baylibre.com> Cc: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Cc: Taichi Sugaya <sugaya.taichi@socionext.com> Cc: Takao Orito <orito.takao@socionext.com> Cc: Bjorn Andersson <andersson@kernel.org> Cc: Konrad Dybcio <konrad.dybcio@linaro.org> Cc: Pali Rohár <pali@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org> Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com> Cc: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Cc: Alim Akhtar <alim.akhtar@samsung.com> Cc: Laxman Dewangan <ldewangan@nvidia.com> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Jonathan Hunter <jonathanh@nvidia.com> Cc: Orson Zhai <orsonzhai@gmail.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Chunyan Zhang <zhang.lyra@gmail.com> Cc: Patrice Chotard <patrice.chotard@foss.st.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Alexandre Torgue <alexandre.torgue@foss.st.com> Cc: David S. Miller <davem@davemloft.net> Cc: Hammer Hsieh <hammerh0314@gmail.com> Cc: Peter Korsgaard <jacmet@sunsite.dk> Cc: Timur Tabi <timur@kernel.org> Cc: Michal Simek <michal.simek@amd.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Christian König <christian.koenig@amd.com> Link: https://lore.kernel.org/r/20240405060826.2521-13-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: Lock console when calling into driver before registrationPeter Collingbourne2024-03-051-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | During the handoff from earlycon to the real console driver, we have two separate drivers operating on the same device concurrently. In the case of the 8250 driver these concurrent accesses cause problems due to the driver's use of banked registers, controlled by LCR.DLAB. It is possible for the setup(), config_port(), pm() and set_mctrl() callbacks to set DLAB, which can cause the earlycon code that intends to access TX to instead access DLL, leading to missed output and corruption on the serial line due to unintended modifications to the baud rate. In particular, for setup() we have: univ8250_console_setup() -> serial8250_console_setup() -> uart_set_options() -> serial8250_set_termios() -> serial8250_do_set_termios() -> serial8250_do_set_divisor() For config_port() we have: serial8250_config_port() -> autoconfig() For pm() we have: serial8250_pm() -> serial8250_do_pm() -> serial8250_set_sleep() For set_mctrl() we have (for some devices): serial8250_set_mctrl() -> omap8250_set_mctrl() -> __omap8250_set_mctrl() To avoid such problems, let's make it so that the console is locked during pre-registration calls to these callbacks, which will prevent the earlycon driver from running concurrently. Remove the partial solution to this problem in the 8250 driver that locked the console only during autoconfig_irq(), as this would result in a deadlock with the new approach. The console continues to be locked during autoconfig_irq() because it can only be called through uart_configure_port(). Although this patch introduces more locking than strictly necessary (and in particular it also locks during the call to rs485_config() which is not affected by this issue as far as I can tell), it follows the principle that it is the responsibility of the generic console code to manage the earlycon handoff by ensuring that earlycon and real console driver code cannot run concurrently, and not the individual drivers. Signed-off-by: Peter Collingbourne <pcc@google.com> Reviewed-by: John Ogness <john.ogness@linutronix.de> Link: https://linux-review.googlesource.com/id/I7cf8124dcebf8618e6b2ee543fa5b25532de55d8 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240304214350.501253-1-pcc@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: core: Fix atomicity violation in uart_tiocmgetGui-Dong Han2024-01-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In uart_tiocmget(): result = uport->mctrl; uart_port_lock_irq(uport); result |= uport->ops->get_mctrl(uport); uart_port_unlock_irq(uport); ... return result; In uart_update_mctrl(): uart_port_lock_irqsave(port, &flags); ... port->mctrl = (old & ~clear) | set; ... port->ops->set_mctrl(port, port->mctrl); ... uart_port_unlock_irqrestore(port, flags); An atomicity violation is identified due to the concurrent execution of uart_tiocmget() and uart_update_mctrl(). After assigning result = uport->mctrl, the mctrl value may change in uart_update_mctrl(), leading to a mismatch between the value returned by uport->ops->get_mctrl(uport) and the mctrl value previously read. This can result in uart_tiocmget() returning an incorrect value. This possible bug is found by an experimental static analysis tool developed by our team, BassCheck[1]. This tool analyzes the locking APIs to extract function pairs that can be concurrently executed, and then analyzes the instructions in the paired functions to identify possible concurrency bugs including data races and atomicity violations. The above possible bug is reported when our tool analyzes the source code of Linux 5.17. To address this issue, it is suggested to move the line result = uport->mctrl inside the uart_port_lock block to ensure atomicity and prevent the mctrl value from being altered during the execution of uart_tiocmget(). With this patch applied, our tool no longer reports the bug, with the kernel configuration allyesconfig for x86_64. Due to the absence of the requisite hardware, we are unable to conduct runtime testing of the patch. Therefore, our verification is solely based on code logic analysis. [1] https://sites.google.com/view/basscheck/ Fixes: c5f4644e6c8b ("[PATCH] Serial: Adjust serial locking") Cc: stable@vger.kernel.org Signed-off-by: Gui-Dong Han <2045gemini@gmail.com> Link: https://lore.kernel.org/r/20240112113624.17048-1-2045gemini@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: core, imx: do not set RS485 enabled if it is not supportedLino Sanfilippo2024-01-041-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the imx driver cannot support RS485 it nullifies the ports rs485_supported structure. But it still calls uart_get_rs485_mode() which may set the RS485_ENABLED flag nevertheless. This may lead to an attempt to configure RS485 even if it is not supported when the flag is evaluated in uart_configure_port() at port startup. Avoid this by bailing out of uart_get_rs485_mode() if the RS485_ENABLED flag is not supported by the caller. With this fix a check for RTS availability is now obsolete in the imx driver, since it can not evaluate to true any more. So remove this check. Furthermore the explicit nullifcation of rs485_supported is not needed, since the memory has already been set to zeros at allocation. So remove this, too. Fixes: 00d7a00e2a6f ("serial: imx: Fill in rs485_supported") Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: <stable@vger.kernel.org> Suggested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20240103061818.564-6-l.sanfilippo@kunbus.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: core: make sure RS485 cannot be enabled when it is not supportedLino Sanfilippo2024-01-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Some uart drivers specify a rs485_config() function and then decide later to disable RS485 support for some reason (e.g. imx and ar933). In these cases userspace may be able to activate RS485 via TIOCSRS485 nevertheless, since in uart_set_rs485_config() an existing rs485_config() function indicates that RS485 is supported. Make sure that this is not longer possible by checking the uarts rs485_supported.flags instead and bailing out if SER_RS485_ENABLED is not set. Furthermore instead of returning an empty structure return -ENOTTY if the RS485 configuration is requested via TIOCGRS485 but RS485 is not supported. This has a small impact on userspace visibility but it is consistent with the -ENOTTY error for TIOCGRS485. Fixes: e849145e1fdd ("serial: ar933x: Fill in rs485_supported") Fixes: 55e18c6b6d42 ("serial: imx: Remove serial_rs485 sanitization") Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: <stable@vger.kernel.org> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Link: https://lore.kernel.org/r/20240103061818.564-5-l.sanfilippo@kunbus.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: core: fix sanitizing check for RTS settingsLino Sanfilippo2024-01-041-10/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | Among other things uart_sanitize_serial_rs485() tests the sanity of the RTS settings in a RS485 configuration that has been passed by userspace. If RTS-on-send and RTS-after-send are both set or unset the configuration is adjusted and RTS-after-send is disabled and RTS-on-send enabled. This however makes only sense if both RTS modes are actually supported by the driver. With commit be2e2cb1d281 ("serial: Sanitize rs485_struct") the code does take the driver support into account but only checks if one of both RTS modes are supported. This may lead to the errorneous result of RTS-on-send being set even if only RTS-after-send is supported. Fix this by changing the implemented logic: First clear all unsupported flags in the RS485 configuration, then adjust an invalid RTS setting by taking into account which RTS mode is supported. Cc: <stable@vger.kernel.org> Fixes: be2e2cb1d281 ("serial: Sanitize rs485_struct") Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Link: https://lore.kernel.org/r/20240103061818.564-4-l.sanfilippo@kunbus.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: core: set missing supported flag for RX during TX GPIOLino Sanfilippo2024-01-041-0/+2
| | | | | | | | | | | | | | | If the RS485 feature RX-during-TX is supported by means of a GPIO set the according supported flag. Otherwise setting this feature from userspace may not be possible, since in uart_sanitize_serial_rs485() the passed RS485 configuration is matched against the supported features and unsupported settings are thereby removed and thus take no effect. Cc: <stable@vger.kernel.org> Fixes: 163f080eb717 ("serial: core: Add option to output RS485 RX_DURING_TX state via GPIO") Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Link: https://lore.kernel.org/r/20240103061818.564-3-l.sanfilippo@kunbus.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: Do not hold the port lock when setting rx-during-tx GPIOLino Sanfilippo2024-01-041-2/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | Both the imx and stm32 driver set the rx-during-tx GPIO in rs485_config(). Since this function is called with the port lock held, this can be a problem in case that setting the GPIO line can sleep (e.g. if a GPIO expander is used which is connected via SPI or I2C). Avoid this issue by moving the GPIO setting outside of the port lock into the serial core and thus making it a generic feature. Also with commit c54d48543689 ("serial: stm32: Add support for rs485 RX_DURING_TX output GPIO") the SER_RS485_RX_DURING_TX flag is only set if a rx-during-tx GPIO is _not_ available, which is wrong. Fix this, too. Furthermore reset old GPIO settings in case that changing the RS485 configuration failed. Fixes: c54d48543689 ("serial: stm32: Add support for rs485 RX_DURING_TX output GPIO") Fixes: ca530cfa968c ("serial: imx: Add support for RS485 RX_DURING_TX output GPIO") Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: <stable@vger.kernel.org> Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Link: https://lore.kernel.org/r/20240103061818.564-2-l.sanfilippo@kunbus.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: serial: kgdboc: Fix 8250_* kgdb over serialMichael Trimarchi2024-01-041-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Check if port type is not PORT_UNKNOWN during poll_init. The kgdboc calls the tty_find_polling_driver that check if the serial is able to use poll_init. The poll_init calls the uart uart_poll_init that try to configure the uart with the selected boot parameters. The uart must be ready before setting parameters. Seems that PORT_UNKNOWN is already used by other functions in serial_core to detect uart status, so use the same to avoid to use it in invalid state. The crash happen for instance in am62x architecture where the 8250 register the platform driver after the 8250 core is initialized. Follow the report crash coming from KGDB Thread 2 received signal SIGSEGV, Segmentation fault. [Switching to Thread 1] _outb (addr=<optimized out>, value=<optimized out>) at ./include/asm-generic/io.h:584 584 __raw_writeb(value, PCI_IOBASE + addr); (gdb) bt This section of the code is too early because in this case the omap serial is not probed Thread 2 received signal SIGSEGV, Segmentation fault. [Switching to Thread 1] _outb (addr=<optimized out>, value=<optimized out>) at ./include/asm-generic/io.h:584 584 __raw_writeb(value, PCI_IOBASE + addr); (gdb) bt Thread 2 received signal SIGSEGV, Segmentation fault. [Switching to Thread 1] _outb (addr=<optimized out>, value=<optimized out>) at ./include/asm-generic/io.h:584 584 __raw_writeb(value, PCI_IOBASE + addr); (gdb) bt 0 _outb (addr=<optimized out>, value=<optimized out>) at ./include/asm-generic/io.h:584 1 logic_outb (value=0 '\000', addr=18446739675637874689) at lib/logic_pio.c:299 2 0xffff80008082dfcc in io_serial_out (p=0x0, offset=16760830, value=0) at drivers/tty/serial/8250/8250_port.c:416 3 0xffff80008082fe34 in serial_port_out (value=<optimized out>, offset=<optimized out>, up=<optimized out>) at ./include/linux/serial_core.h:677 4 serial8250_do_set_termios (port=0xffff8000828ee940 <serial8250_ports+1568>, termios=0xffff80008292b93c, old=0x0) at drivers/tty/serial/8250/8250_port.c:2860 5 0xffff800080830064 in serial8250_set_termios (port=0xfffffbfffe800000, termios=0xffbffe, old=0x0) at drivers/tty/serial/8250/8250_port.c:2912 6 0xffff80008082571c in uart_set_options (port=0xffff8000828ee940 <serial8250_ports+1568>, co=0x0, baud=115200, parity=110, bits=8, flow=110) at drivers/tty/serial/serial_core.c:2285 7 0xffff800080828434 in uart_poll_init (driver=0xfffffbfffe800000, line=16760830, options=0xffff8000828f7506 <config+6> "115200n8") at drivers/tty/serial/serial_core.c:2656 8 0xffff800080801690 in tty_find_polling_driver (name=0xffff8000828f7500 <config> "ttyS2,115200n8", line=0xffff80008292ba90) at drivers/tty/tty_io.c:410 9 0xffff80008086c0b0 in configure_kgdboc () at drivers/tty/serial/kgdboc.c:194 10 0xffff80008086c1ec in kgdboc_probe (pdev=0xfffffbfffe800000) at drivers/tty/serial/kgdboc.c:249 11 0xffff8000808b399c in platform_probe (_dev=0xffff000000ebb810) at drivers/base/platform.c:1404 12 0xffff8000808b0b44 in call_driver_probe (drv=<optimized out>, dev=<optimized out>) at drivers/base/dd.c:579 13 really_probe (dev=0xffff000000ebb810, drv=0xffff80008277f138 <kgdboc_platform_driver+48>) at drivers/base/dd.c:658 14 0xffff8000808b0d2c in __driver_probe_device (drv=0xffff80008277f138 <kgdboc_platform_driver+48>, dev=0xffff000000ebb810) at drivers/base/dd.c:800 15 0xffff8000808b0eb8 in driver_probe_device (drv=0xfffffbfffe800000, dev=0xffff000000ebb810) at drivers/base/dd.c:830 16 0xffff8000808b0ff4 in __device_attach_driver (drv=0xffff80008277f138 <kgdboc_platform_driver+48>, _data=0xffff80008292bc48) at drivers/base/dd.c:958 17 0xffff8000808ae970 in bus_for_each_drv (bus=0xfffffbfffe800000, start=0x0, data=0xffff80008292bc48, fn=0xffff8000808b0f3c <__device_attach_driver>) at drivers/base/bus.c:457 18 0xffff8000808b1408 in __device_attach (dev=0xffff000000ebb810, allow_async=true) at drivers/base/dd.c:1030 19 0xffff8000808b16d8 in device_initial_probe (dev=0xfffffbfffe800000) at drivers/base/dd.c:1079 20 0xffff8000808af9f4 in bus_probe_device (dev=0xffff000000ebb810) at drivers/base/bus.c:532 21 0xffff8000808ac77c in device_add (dev=0xfffffbfffe800000) at drivers/base/core.c:3625 22 0xffff8000808b3428 in platform_device_add (pdev=0xffff000000ebb800) at drivers/base/platform.c:716 23 0xffff800081b5dc0c in init_kgdboc () at drivers/tty/serial/kgdboc.c:292 24 0xffff800080014db0 in do_one_initcall (fn=0xffff800081b5dba4 <init_kgdboc>) at init/main.c:1236 25 0xffff800081b0114c in do_initcall_level (command_line=<optimized out>, level=<optimized out>) at init/main.c:1298 26 do_initcalls () at init/main.c:1314 27 do_basic_setup () at init/main.c:1333 28 kernel_init_freeable () at init/main.c:1551 29 0xffff8000810271ec in kernel_init (unused=0xfffffbfffe800000) at init/main.c:1441 30 0xffff800080015e80 in ret_from_fork () at arch/arm64/kernel/entry.S:857 Reviewed-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com> Link: https://lore.kernel.org/r/20231224131200.266224-1-michael@amarulasolutions.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: serial: Add RS422 flag to struct serial_rs485Crescent CY Hsieh2024-01-041-0/+6
| | | | | | | | | | | | | | | Add "SER_RS485_MODE_RS422" flag to struct serial_rs485, so that serial port can switch interface into RS422 if supported by using ioctl command "TIOCSRS485". By treating RS422 as a mode of RS485, which means while enabling RS422 there are two flags need to be set (SER_RS485_ENABLED and SER_RS485_MODE_RS422), it would make things much easier. For example some places that checks for "SER_RS485_ENABLED" won't need to be rewritten. Signed-off-by: Crescent CY Hsieh <crescentcy.hsieh@moxa.com> Link: https://lore.kernel.org/r/20231201071554.258607-3-crescentcy.hsieh@moxa.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: core: Clean up uart_update_timeout() functionVamshi Gajjela2024-01-041-4/+3
| | | | | | | | | | | | | | | | | | | | | | | Rename the variable size to temp and change its data type from unsigned int to u64 to avoid type casting in multiplication. Remove the intermediate variable frame_time and use temp instead to accommodate the nanoseconds(ns). port->frame_time is an unsigned int, therefore an explicit cast is used to improve readability. Having said this unsigned int is sufficinet to hold frame time duration in nanoseconds for all the standard baudrates. Consider 9600 baud, it takes 1/9600 seconds for one bit, for a total of 10 bits (start, 8-bit data, stop) 10/9600=1.04 ms for 1 byte transfer, frame_time here is 1041667ns. As baudrate increases frame_time decreases, say for 115200 baud it is 86806ns. To avoid costly 64-bit arithmetic we do not upconvert the type for variable frame_time as overflow happens for extremely low baudrates which are impractical and are not used in real-world applications. Signed-off-by: Vamshi Gajjela <vamshigajjela@google.com> Link: https://lore.kernel.org/r/20231109063417.3971005-3-vamshigajjela@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: make tty_operations::send_xchar accept u8 charJiri Slaby (SUSE)2023-12-081-1/+1
| | | | | | | | | | | | | | | | | | tty_operations::send_xchar is one of the last users of 'char' type for characters in the tty layer. Convert it to u8 now. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Karsten Keil <isdn@linux-pingi.de> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Marcel Holtmann <marcel@holtmann.org> Cc: Johan Hedberg <johan.hedberg@gmail.com> Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com> Cc: netdev@vger.kernel.org Cc: linux-mmc@vger.kernel.org Cc: linux-bluetooth@vger.kernel.org Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> Link: https://lore.kernel.org/r/20231206073712.17776-5-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: core: Revert checks for tx runtime PM stateTony Lindgren2023-11-251-1/+1
| | | | | | | | | | | | | | | This reverts commit 81a61051e0ce5fd7e09225c0d5985da08c7954a7. With tty and serdev controller moved to be children of the serial core port device, runtime PM usage count of the serdev controller now propagates to the serial hardware controller parent device as expected. Cc: Maximilian Luz <luzmaximilian@gmail.com> Cc: Rob Herring <robh@kernel.org> Signed-off-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20231113080758.30346-2-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: core: Move tty and serdev to be children of serial core port deviceTony Lindgren2023-11-251-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Let's move tty and serdev controller to be children of the serial core port device. This way the runtime PM usage count of a child device propagates to the serial hardware device. The tty and serdev devices are associated with a specific serial port of a serial hardware controller device, and we now have serial core hierarchy of controllers and ports. The tty device moves happily with just a change of the parent device and update of device_find_child() handling. The serdev device init needs some changes to separate the serial hardware controller device from the parent device. With this change the tty devices move under sysfs similar to this x86_64 qemu example of a diff of "find /sys -name ttyS*": /sys/class/tty/ttyS0 /sys/class/tty/ttyS3 /sys/class/tty/ttyS1 -/sys/devices/pnp0/00:04/tty/ttyS0 -/sys/devices/platform/serial8250/tty/ttyS2 -/sys/devices/platform/serial8250/tty/ttyS3 -/sys/devices/platform/serial8250/tty/ttyS1 +/sys/devices/pnp0/00:04/00:04:0/00:04:0.0/tty/ttyS0 +/sys/devices/platform/serial8250/serial8250:0/serial8250:0.3/tty/ttyS3 +/sys/devices/platform/serial8250/serial8250:0/serial8250:0.1/tty/ttyS1 +/sys/devices/platform/serial8250/serial8250:0/serial8250:0.2/tty/ttyS2 If a serdev device is used instead of a tty, it moves in a similar way. Suggested-by: Johan Hovold <johan@kernel.org> Cc: Maximilian Luz <luzmaximilian@gmail.com> Cc: Rob Herring <robh@kernel.org> Signed-off-by: Tony Lindgren <tony@atomide.com> Link: https://lore.kernel.org/r/20231113080758.30346-1-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: core: Fix runtime PM handling for pending txTony Lindgren2023-10-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | Richard reported that a serial port may end up sometimes with tx data pending in the buffer for long periods of time. Turns out we bail out early on any errors from pm_runtime_get(), including -EINPROGRESS. To fix the issue, we need to ignore -EINPROGRESS as we only care about the runtime PM usage count at this point. We check for an active runtime PM state later on for tx. Fixes: 84a9582fd203 ("serial: core: Start managing serial controllers to enable runtime PM") Cc: stable <stable@kernel.org> Reported-by: Richard Purdie <richard.purdie@linuxfoundation.org> Cc: Bruce Ashfield <bruce.ashfield@gmail.com> Cc: Mikko Rapeli <mikko.rapeli@linaro.org> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Randy MacLeod <randy.macleod@windriver.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Tested-by: Richard Purdie <richard.purdie@linuxfoundation.org> Link: https://lore.kernel.org/r/20231023074856.61896-1-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: core: tidy invalid baudrate handling in uart_get_baud_rateMax Filippov2023-10-161-3/+1
| | | | | | | | | | | | | | | | uart_get_baud_rate has input parameters 'min' and 'max' limiting the range of acceptable baud rates from the caller's perspective. If neither current or old termios structures have acceptable baud rate setting and 9600 is not in the min/max range either the function returns 0 and issues a warning. However for a UART that does not support speed of 9600 baud this is expected behavior. Clarify that 0 can be (and always could be) returned from the uart_get_baud_rate. Don't issue a warning in that case. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Link: https://lore.kernel.org/r/20231010085926.1021667-2-jcmvbkbc@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge 6.6-rc6 into tty-nextGreg Kroah-Hartman2023-10-161-5/+10
|\ | | | | | | | | | | | | | | | | | | We need the tty/serial fixes in here as well for testing, and this resolves merge conflicts in: drivers/tty/serial/serial_core.c as reported in linux-next Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * serial: core: Fix checks for tx runtime PM stateTony Lindgren2023-10-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Maximilian reported that surface_serial_hub serdev tx does not work during system suspend. During system suspend, runtime PM gets disabled in __device_suspend_late(), and tx is unable to wake-up the serial core port device that we use to check if tx is safe to start. Johan summarized the regression noting that serdev tx no longer always works as earlier when the serdev device is runtime PM active. The serdev device and the serial core controller devices are siblings of the serial port hardware device. The runtime PM usage count from serdev device does not propagate to the serial core device siblings, it only propagates to the parent. In addition to the tx issue for suspend, testing for the serial core port device can cause an unnecessary delay in enabling tx while waiting for the serial core port device to wake-up. The serial core port device wake-up is only needed to flush pending tx when the serial port hardware device was in runtime PM suspended state. To fix the regression, we need to check the runtime PM state of the parent serial port hardware device for tx instead of the serial core port device. As the serial port device drivers may or may not implement runtime PM, we need to also add a check for pm_runtime_enabled(). Reported-by: Maximilian Luz <luzmaximilian@gmail.com> Cc: stable <stable@kernel.org> Fixes: 84a9582fd203 ("serial: core: Start managing serial controllers to enable runtime PM") Signed-off-by: Tony Lindgren <tony@atomide.com> Tested-by: Maximilian Luz <luzmaximilian@gmail.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20231005075644.25936-1-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * serial: Reduce spinlocked portion of uart_rs485_config()Lukas Wunner2023-10-031-4/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 44b27aec9d96 ("serial: core, 8250: set RS485 termination GPIO in serial core") enabled support for RS485 termination GPIOs behind i2c expanders by setting the GPIO outside of the critical section protected by the port spinlock. Access to the i2c expander may sleep, which caused a splat with the port spinlock held. Commit 7c7f9bc986e6 ("serial: Deassert Transmit Enable on probe in driver-specific way") erroneously regressed that by spinlocking the GPIO manipulation again. Fix by moving uart_rs485_config() (the function manipulating the GPIO) outside of the spinlocked section and acquiring the spinlock inside of uart_rs485_config() for the invocation of ->rs485_config() only. This gets us one step closer to pushing the spinlock down into the ->rs485_config() callbacks which actually need it. (Some callbacks do not want to be spinlocked because they perform sleepable register accesses, see e.g. sc16is7xx_config_rs485().) Stack trace for posterity: Voluntary context switch within RCU read-side critical section! WARNING: CPU: 0 PID: 56 at kernel/rcu/tree_plugin.h:318 rcu_note_context_switch Call trace: rcu_note_context_switch __schedule schedule schedule_timeout wait_for_completion_timeout bcm2835_i2c_xfer __i2c_transfer i2c_transfer i2c_transfer_buffer_flags regmap_i2c_write _regmap_raw_write_impl _regmap_bus_raw_write _regmap_write _regmap_update_bits regmap_update_bits_base pca953x_gpio_set_value gpiod_set_raw_value_commit gpiod_set_value_nocheck gpiod_set_value_cansleep uart_rs485_config uart_add_one_port pl011_register_port pl011_probe Fixes: 7c7f9bc986e6 ("serial: Deassert Transmit Enable on probe in driver-specific way") Suggested-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> Signed-off-by: Lukas Wunner <lukas@wunner.de> Cc: stable@vger.kernel.org # v6.1+ Link: https://lore.kernel.org/r/f3a35967c28b32f3c6432d0aa5936e6a9908282d.1695307688.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | serial: initialize retinfo in uart_get_info()Alexey Dobriyan2023-10-071-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If this check ever triggers static int uart_get_info(struct tty_port *port, struct serial_struct *retinfo) { uport = uart_port_check(state); if (!uport) goto out; then all those sysfs users will print stack contents to userspace. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Link: https://lore.kernel.org/r/967b9ef1-fb36-48bf-9e6a-1b99af24c052@p183 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | serial: core: Simplify uart_get_rs485_mode()Andy Shevchenko2023-10-051-18/+12
| | | | | | | | | | | | | | | | | | | | Simplify uart_get_rs485_mode() by using temporary variable for the GPIO descriptor. With that, use proper type for the flags of the GPIO descriptor. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20231003142346.3072929-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | serial: core: Use port lock wrappersThomas Gleixner2023-09-181-44/+44
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a serial port is used for kernel console output, then all modifications to the UART registers which are done from other contexts, e.g. getty, termios, are interference points for the kernel console. So far this has been ignored and the printk output is based on the principle of hope. The rework of the console infrastructure which aims to support threaded and atomic consoles, requires to mark sections which modify the UART registers as unsafe. This allows the atomic write function to make informed decisions and eventually to restore operational state. It also allows to prevent the regular UART code from modifying UART registers while printk output is in progress. All modifications of UART registers are guarded by the UART port lock, which provides an obvious synchronization point with the console infrastructure. To avoid adding this functionality to all UART drivers, wrap the spin_[un]lock*() invocations for uart_port::lock into helper functions which just contain the spin_[un]lock*() invocations for now. In a subsequent step these helpers will gain the console synchronization mechanisms. Converted with coccinelle. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Ogness <john.ogness@linutronix.de> Link: https://lore.kernel.org/r/20230914183831.587273-58-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: make tty_operations::write()'s count size_tJiri Slaby (SUSE)2023-08-111-1/+1
| | | | | | | | | Unify with the rest of the code. Use size_t for counts and ssize_t for retval. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20230810091510.13006-30-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: propagate u8 data to tty_operations::put_char()Jiri Slaby (SUSE)2023-08-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | Data are now typed as u8. Propagate this change to tty_operations::put_char(). Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Karsten Keil <isdn@linux-pingi.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Pengutronix Kernel Team <kernel@pengutronix.de> Cc: Fabio Estevam <festevam@gmail.com> Cc: NXP Linux Team <linux-imx@nxp.com> Cc: Mathias Nyman <mathias.nyman@intel.com> Link: https://lore.kernel.org/r/20230810091510.13006-29-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: propagate u8 data to tty_operations::write()Jiri Slaby (SUSE)2023-08-111-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Data are now typed as u8. Propagate this change to tty_operations::write(). Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Richard Henderson <richard.henderson@linaro.org> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Richard Weinberger <richard@nod.at> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Vaibhav Gupta <vaibhavgupta40@gmail.com> Cc: Jens Taprogge <jens.taprogge@taprogge.org> Cc: Karsten Keil <isdn@linux-pingi.de> Cc: Scott Branden <scott.branden@broadcom.com> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: David Lin <dtwlin@gmail.com> Cc: Johan Hovold <johan@kernel.org> Cc: Alex Elder <elder@kernel.org> Cc: Laurentiu Tudor <laurentiu.tudor@nxp.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: David Sterba <dsterba@suse.com> Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Pengutronix Kernel Team <kernel@pengutronix.de> Cc: Fabio Estevam <festevam@gmail.com> Cc: NXP Linux Team <linux-imx@nxp.com> Cc: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com> Cc: Oliver Neukum <oneukum@suse.com> Cc: Mathias Nyman <mathias.nyman@intel.com> Cc: Marcel Holtmann <marcel@holtmann.org> Cc: Johan Hedberg <johan.hedberg@gmail.com> Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com> Link: https://lore.kernel.org/r/20230810091510.13006-28-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: move WARN_ON() in uart_write() to the conditionJiri Slaby2023-07-311-6/+2
| | | | | | | | | | | | | | | | | | | uart code currently does the following in uart_write() and uart_flush_buffer(): if (cond) { WARN_ON(1); return; } It can be rewritten to more obvious and more readable: if (WARN_ON(cond)) return; Do so. Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20230731080244.2698-2-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: pass state to __uart_start() directlyJiri Slaby2023-07-251-5/+4
| | | | | | | | | __uart_start() does not need a tty struct. It works only with uart_state. So pass the latter directly. Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20230712081811.29004-8-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: make uart_insert_char() accept u8sJiri Slaby2023-07-251-1/+1
| | | | | | | | | Both the character and flag are 8-bit values. So switch from unsigned ints to u8s. The drivers will be cleaned up in the next round. Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20230712081811.29004-7-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: convert uart sysrq handling to u8Jiri Slaby2023-07-251-2/+2
| | | | | | | | | Propagate u8 from the sysrq code further up to serial's uart_handle_sysrq_char() and friends. Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20230712081811.29004-6-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: core: Fix error handling for serial_core_ctrl_device_add()Tony Lindgren2023-06-021-2/+2
| | | | | | | | | | | | | Checking for NULL is incorrect as serial_base_ctrl_add() uses ERR_PTR(). Let's also pass any returned error along, there's no reason to translate all errors to -ENODEV. Fixes: 84a9582fd203 ("serial: core: Start managing serial controllers to enable runtime PM") Signed-off-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20230602070007.59268-1-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: core: Don't drop port_mutex in serial_core_remove_one_portSteven Price2023-06-011-3/+1
| | | | | | | | | | | | | | | Commit 84a9582fd203 ("serial: core: Start managing serial controllers to enable runtime PM") required the caller to hold port_mutex rather than taking it locally. However the mutex_unlock() call wasn't removed causing the mutex to be dropped unexpectly. Remove the call to mutex_unlock() (and fix up the early return) to restore correct behaviour. Fixes: 84a9582fd203 ("serial: core: Start managing serial controllers to enable runtime PM") Signed-off-by: Steven Price <steven.price@arm.com> Reviewed-by: Tony Lindgren <tony@atomide.com> Link: https://lore.kernel.org/r/20230601105548.29965-1-steven.price@arm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: core: Start managing serial controllers to enable runtime PMTony Lindgren2023-05-311-21/+171
| | | | | | | | | | | | | | | | | | | | | | | | | | | We want to enable runtime PM for serial port device drivers in a generic way. To do this, we want to have the serial core layer manage the registered physical serial controller devices. To manage serial controllers, let's set up a struct bus and struct device for the serial core controller as suggested by Greg and Jiri. The serial core controller devices are children of the physical serial port device. The serial core controller device is needed to support multiple different kind of ports connected to single physical serial port device. Let's also set up a struct device for the serial core port. The serial core port instances are children of the serial core controller device. With the serial core port device we can now flush pending TX on the runtime PM resume as suggested by Johan. Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Suggested-by: Jiri Slaby <jirislaby@kernel.org> Suggested-by: Johan Hovold <johan@kernel.org> Signed-off-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20230525113034.46880-1-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: core: lock port for start_rx() in uart_resume_port()John Ogness2023-05-301-1/+4
| | | | | | | | | | | | | The only user of the start_rx() callback (qcom_geni) directly calls its own stop_rx() callback. Since stop_rx() requires that the port->lock is taken and interrupts are disabled, the start_rx() callback has the same requirement. Fixes: cfab87c2c271 ("serial: core: Introduce callback for start_rx and do stop_rx in suspend only if this callback implementation is present.") Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20230525093159.223817-5-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: core: lock port for stop_rx() in uart_suspend_port()John Ogness2023-05-301-1/+4
| | | | | | | | | | | The uarts_ops stop_rx() callback expects that the port->lock is taken and interrupts are disabled. Fixes: c9d2325cdb92 ("serial: core: Do stop_rx in suspend path for console if console_suspend is disabled") Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20230525093159.223817-3-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: Make uart_remove_one_port() return voidUwe Kleine-König2023-05-131-5/+1
| | | | | | | | | | | | | | | The return value is only ever used as a return value for remove callbacks of platform drivers. This return value is ignored by the driver core. (The only effect is an error message, but uart_remove_one_port() already emitted one in this case.) So the return value isn't used at all and uart_remove_one_port() can be changed to return void without any loss. Also this better matches the Linux device model as remove functions are not supposed to fail. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20230512173810.131447-3-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: core: Disable uart_start() on uart_remove_one_port()Tony Lindgren2023-04-201-1/+1
| | | | | | | | | | | | | | | | | | While rebinding a uart device in a loop I noticed we may see a tx related race on uart_remove_one_port(): uart_write from n_tty_write n_tty_write from file_tty_write.constprop.0 file_tty_write.constprop.0 from vfs_write vfs_write from ksys_write ksys_write from ret_fast_syscall Let's disallow tx on port->UPF_DEAD. This flag gets set before we start tearing down the port in uart_remove_one_port(). Signed-off-by: Tony Lindgren <tony@atomide.com> Link: https://lore.kernel.org/r/20230419115423.59957-1-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: fix TIOCSRS485 lockingJohan Hovold2023-04-201-2/+2
| | | | | | | | | | | | | | | | | The RS485 multipoint addressing support for some reason added a new ADDRB termios cflag which is (only!) updated from one of the RS485 ioctls. Make sure to take the termios rw semaphore for the right ioctl (i.e. set, not get). Fixes: ae50bb275283 ("serial: take termios_rwsem for ->rs485_config() & pass termios as param") Cc: stable@vger.kernel.org # 6.0 Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20230412124811.11217-1-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: uart_poll_init() should power on the UARTDouglas Anderson2023-03-291-0/+6
| | | | | | | | | | | | | On Qualcomm devices which use the "geni" serial driver, kdb/kgdb won't be very happy if you use it but the resources of the port haven't been powered on. Today kdb/kgdb rely on someone else powering the port on. This could be the normal kernel console or an agetty running. Let's fix this to explicitly power things on when setting up a polling driver. Signed-off-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20230316132027.RESEND.1.I106c39498d8094c6f5e7ada42c7db17aa5c64e48@changeid Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: Remove uart_wait_until_sent() forward declarationIlpo Järvinen2023-03-171-1/+0
| | | | | | | | Remove unnecessary forward declaration of uart_wait_until_sent(). Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230309080923.11778-9-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: Rename hw_stopped to old_hw_stopped & improve logicIlpo Järvinen2023-03-171-6/+5
| | | | | | | | | | | | | hw_stopped in uart_change_line_settings() stores old hw_stopped, thus rename it appropriately. Alter logic to check first if the hw_stopped was changed, and then pick which function to call if it was because the logic is more obvious that way. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230309080923.11778-8-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: Make hw_stopped boolIlpo Järvinen2023-03-171-3/+3
| | | | | | | | | | | | Convert hw_stopped in uart_port to bool because its more appropriate type for how it is used. Also convert the local variable in uart_change_line_settings() caching old hw_stopped to bool. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230309080923.11778-7-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-15 23:35:10 +0000