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| * | | ARM: s3c: remove s3c24xx specific hacksArnd Bergmann2023-01-162-203/+4
| |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A number of device drivers reference CONFIG_ARM_S3C24XX_CPUFREQ or similar symbols that are no longer available with the platform gone, though the drivers themselves are still used on newer platforms, so remove these hacks. Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Miquel Raynal <miquel.raynal@bootlin.com> Acked-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Stephen Boyd <sboyd@kernel.org> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
* | | serial: 8250_dma: Fix DMA Rx rearm raceIlpo Järvinen2023-01-311-2/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As DMA Rx can be completed from two places, it is possible that DMA Rx completes before DMA completion callback had a chance to complete it. Once the previous DMA Rx has been completed, a new one can be started on the next UART interrupt. The following race is possible (uart_unlock_and_check_sysrq_irqrestore() replaced with spin_unlock_irqrestore() for simplicity/clarity): CPU0 CPU1 dma_rx_complete() serial8250_handle_irq() spin_lock_irqsave(&port->lock) handle_rx_dma() serial8250_rx_dma_flush() __dma_rx_complete() dma->rx_running = 0 // Complete DMA Rx spin_unlock_irqrestore(&port->lock) serial8250_handle_irq() spin_lock_irqsave(&port->lock) handle_rx_dma() serial8250_rx_dma() dma->rx_running = 1 // Setup a new DMA Rx spin_unlock_irqrestore(&port->lock) spin_lock_irqsave(&port->lock) // sees dma->rx_running = 1 __dma_rx_complete() dma->rx_running = 0 // Incorrectly complete // running DMA Rx This race seems somewhat theoretical to occur for real but handle it correctly regardless. Check what is the DMA status before complething anything in __dma_rx_complete(). Reported-by: Gilles BULOZ <gilles.buloz@kontron.com> Tested-by: Gilles BULOZ <gilles.buloz@kontron.com> Fixes: 9ee4b83e51f7 ("serial: 8250: Add support for dmaengine") Cc: stable@vger.kernel.org Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230130114841.25749-3-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | | serial: 8250_dma: Fix DMA Rx completion raceIlpo Järvinen2023-01-311-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | __dma_rx_complete() is called from two places: - Through the DMA completion callback dma_rx_complete() - From serial8250_rx_dma_flush() after IIR_RLSI or IIR_RX_TIMEOUT The former does not hold port's lock during __dma_rx_complete() which allows these two to race and potentially insert the same data twice. Extend port's lock coverage in dma_rx_complete() to prevent the race and check if the DMA Rx is still pending completion before calling into __dma_rx_complete(). Reported-by: Gilles BULOZ <gilles.buloz@kontron.com> Tested-by: Gilles BULOZ <gilles.buloz@kontron.com> Fixes: 9ee4b83e51f7 ("serial: 8250: Add support for dmaengine") Cc: stable@vger.kernel.org Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230130114841.25749-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | | serial: stm32: Merge hard IRQ and threaded IRQ handling into single IRQ handlerMarek Vasut2023-01-311-28/+5
| |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Requesting an interrupt with IRQF_ONESHOT will run the primary handler in the hard-IRQ context even in the force-threaded mode. The force-threaded mode is used by PREEMPT_RT in order to avoid acquiring sleeping locks (spinlock_t) in hard-IRQ context. This combination makes it impossible and leads to "sleeping while atomic" warnings. Use one interrupt handler for both handlers (primary and secondary) and drop the IRQF_ONESHOT flag which is not needed. Fixes: e359b4411c283 ("serial: stm32: fix threaded interrupt handling") Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Tested-by: Valentin Caron <valentin.caron@foss.st.com> # V3 Signed-off-by: Marek Vasut <marex@denx.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230120160332.57930-1-marex@denx.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | Merge tag 'tty-6.2-rc5' of ↵Linus Torvalds2023-01-215-20/+44
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial driver fixes from Greg KH: "Here are some small tty and serial driver fixes for 6.2-rc5 that resolve a number of tiny reported issues and some new device ids. They include: - new device id for the exar serial driver - speakup tty driver bugfix - atmel serial driver baudrate fixup - stm32 serial driver bugfix and then revert as the bugfix broke the build. That will come back in a later pull request once it is all worked out properly. - amba-pl011 serial driver rs486 mode bugfix - qcom_geni serial driver bugfix Most of these have been in linux-next with no reported problems (well, other than the build breakage which generated the revert), the new device id passed 0-day testing" * tag 'tty-6.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: serial: exar: Add support for Sealevel 7xxxC serial cards Revert "serial: stm32: Merge hard IRQ and threaded IRQ handling into single IRQ handler" tty: serial: qcom_geni: avoid duplicate struct member init serial: atmel: fix incorrect baudrate setup tty: fix possible null-ptr-defer in spk_ttyio_release serial: stm32: Merge hard IRQ and threaded IRQ handling into single IRQ handler serial: amba-pl011: fix high priority character transmission in rs486 mode serial: pch_uart: Pass correct sg to dma_unmap_sg() tty: serial: qcom-geni-serial: fix slab-out-of-bounds on RX FIFO buffer
| * | serial: exar: Add support for Sealevel 7xxxC serial cardsMatthew Howell2023-01-201-0/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add support for Sealevel 7xxxC serial cards. This patch: * Adds IDs to recognize 7xxxC cards from Sealevel Systems. * Updates exar_pci_probe() to set nr_ports to last two bytes of primary dev ID for these cards. Signed-off-by: Matthew Howell <matthew.howell@sealevel.com> Cc: stable <stable@kernel.org> Link: https://lore.kernel.org/r/alpine.DEB.2.21.2301191440010.22558@tstest-VirtualBox Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | Revert "serial: stm32: Merge hard IRQ and threaded IRQ handling into single ↵Greg Kroah-Hartman2023-01-201-4/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | IRQ handler" This reverts commit f24771b62a83239f0dce816bddf0f6807f436235 as it is reported to break the build. Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/r/202301200130.ttBiTzfO-lkp@intel.com Fixes: f24771b62a83 ("serial: stm32: Merge hard IRQ and threaded IRQ handling into single IRQ handler") Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Valentin Caron <valentin.caron@foss.st.com> # V3 Cc: Marek Vasut <marex@denx.de> Cc: Johan Hovold <johan@kernel.org> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | tty: serial: qcom_geni: avoid duplicate struct member initArnd Bergmann2023-01-191-6/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When -Woverride-init is enabled in a build, gcc points out that qcom_geni_serial_pm_ops contains conflicting initializers: drivers/tty/serial/qcom_geni_serial.c:1586:20: error: initialized field overwritten [-Werror=override-init] 1586 | .restore = qcom_geni_serial_sys_hib_resume, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/tty/serial/qcom_geni_serial.c:1586:20: note: (near initialization for 'qcom_geni_serial_pm_ops.restore') drivers/tty/serial/qcom_geni_serial.c:1587:17: error: initialized field overwritten [-Werror=override-init] 1587 | .thaw = qcom_geni_serial_sys_hib_resume, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Open-code the initializers with the version that was already used, and use the pm_sleep_ptr() method to deal with unused ones, in place of the __maybe_unused annotation. Fixes: 35781d8356a2 ("tty: serial: qcom-geni-serial: Add support for Hibernation feature") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20221215165453.1864836-1-arnd@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | serial: atmel: fix incorrect baudrate setupTobias Schramm2023-01-191-7/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit ba47f97a18f2 ("serial: core: remove baud_rates when serial console setup") changed uart_set_options to select the correct baudrate configuration based on the absolute error between requested baudrate and available standard baudrate settings. Prior to that commit the baudrate was selected based on which predefined standard baudrate did not exceed the requested baudrate. This change of selection logic was never reflected in the atmel serial driver. Thus the comment left in the atmel serial driver is no longer accurate. Additionally the manual rounding up described in that comment and applied via (quot - 1) requests an incorrect baudrate. Since uart_set_options uses tty_termios_encode_baud_rate to determine the appropriate baudrate flags this can cause baudrate selection to fail entirely because tty_termios_encode_baud_rate will only select a baudrate if relative error between requested and selected baudrate does not exceed +/-2%. Fix that by requesting actual, exact baudrate used by the serial. Fixes: ba47f97a18f2 ("serial: core: remove baud_rates when serial console setup") Cc: stable <stable@kernel.org> Signed-off-by: Tobias Schramm <t.schramm@manjaro.org> Acked-by: Richard Genoud <richard.genoud@gmail.com> Link: https://lore.kernel.org/r/20230109072940.202936-1-t.schramm@manjaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | serial: stm32: Merge hard IRQ and threaded IRQ handling into single IRQ handlerMarek Vasut2023-01-191-27/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Requesting an interrupt with IRQF_ONESHOT will run the primary handler in the hard-IRQ context even in the force-threaded mode. The force-threaded mode is used by PREEMPT_RT in order to avoid acquiring sleeping locks (spinlock_t) in hard-IRQ context. This combination makes it impossible and leads to "sleeping while atomic" warnings. Use one interrupt handler for both handlers (primary and secondary) and drop the IRQF_ONESHOT flag which is not needed. Fixes: e359b4411c283 ("serial: stm32: fix threaded interrupt handling") Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Tested-by: Valentin Caron <valentin.caron@foss.st.com> # V3 Signed-off-by: Marek Vasut <marex@denx.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230112180417.25595-1-marex@denx.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | serial: amba-pl011: fix high priority character transmission in rs486 modeLino Sanfilippo2023-01-191-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In RS485 mode the transmission of a high priority character fails since it is written to the data register before the transmitter is enabled. Fix this in pl011_tx_chars() by enabling RS485 transmission before writing the character. Fixes: 8d479237727c ("serial: amba-pl011: add RS485 support") Cc: stable@vger.kernel.org Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Link: https://lore.kernel.org/r/20230108181735.10937-1-LinoSanfilippo@gmx.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | serial: pch_uart: Pass correct sg to dma_unmap_sg()Ilpo Järvinen2023-01-191-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A local variable sg is used to store scatterlist pointer in pch_dma_tx_complete(). The for loop doing Tx byte accounting before dma_unmap_sg() alters sg in its increment statement. Therefore, the pointer passed into dma_unmap_sg() won't match to the one given to dma_map_sg(). To fix the problem, use priv->sg_tx_p directly in dma_unmap_sg() instead of the local variable. Fixes: da3564ee027e ("pch_uart: add multi-scatter processing") Cc: stable@vger.kernel.org Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230103093435.4396-1-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | tty: serial: qcom-geni-serial: fix slab-out-of-bounds on RX FIFO bufferKrzysztof Kozlowski2023-01-191-2/+16
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Driver's probe allocates memory for RX FIFO (port->rx_fifo) based on default RX FIFO depth, e.g. 16. Later during serial startup the qcom_geni_serial_port_setup() updates the RX FIFO depth (port->rx_fifo_depth) to match real device capabilities, e.g. to 32. The RX UART handle code will read "port->rx_fifo_depth" number of words into "port->rx_fifo" buffer, thus exceeding the bounds. This can be observed in certain configurations with Qualcomm Bluetooth HCI UART device and KASAN: Bluetooth: hci0: QCA Product ID :0x00000010 Bluetooth: hci0: QCA SOC Version :0x400a0200 Bluetooth: hci0: QCA ROM Version :0x00000200 Bluetooth: hci0: QCA Patch Version:0x00000d2b Bluetooth: hci0: QCA controller version 0x02000200 Bluetooth: hci0: QCA Downloading qca/htbtfw20.tlv bluetooth hci0: Direct firmware load for qca/htbtfw20.tlv failed with error -2 Bluetooth: hci0: QCA Failed to request file: qca/htbtfw20.tlv (-2) Bluetooth: hci0: QCA Failed to download patch (-2) ================================================================== BUG: KASAN: slab-out-of-bounds in handle_rx_uart+0xa8/0x18c Write of size 4 at addr ffff279347d578c0 by task swapper/0/0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.1.0-rt5-00350-gb2450b7e00be-dirty #26 Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT) Call trace: dump_backtrace.part.0+0xe0/0xf0 show_stack+0x18/0x40 dump_stack_lvl+0x8c/0xb8 print_report+0x188/0x488 kasan_report+0xb4/0x100 __asan_store4+0x80/0xa4 handle_rx_uart+0xa8/0x18c qcom_geni_serial_handle_rx+0x84/0x9c qcom_geni_serial_isr+0x24c/0x760 __handle_irq_event_percpu+0x108/0x500 handle_irq_event+0x6c/0x110 handle_fasteoi_irq+0x138/0x2cc generic_handle_domain_irq+0x48/0x64 If the RX FIFO depth changes after probe, be sure to resize the buffer. Fixes: f9d690b6ece7 ("tty: serial: qcom_geni_serial: Allocate port->rx_fifo buffer in probe") Cc: <stable@vger.kernel.org> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20221221164022.1087814-1-krzysztof.kozlowski@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | Merge tag 'printk-for-6.2-rc5' of ↵Linus Torvalds2023-01-192-15/+10
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux Pull printk fixes from Petr Mladek: - Prevent a potential deadlock when configuring kgdb console - Fix a kernel doc warning * tag 'printk-for-6.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: kernel/printk/printk.c: Fix W=1 kernel-doc warning tty: serial: kgdboc: fix mutex locking order for configure_kgdboc()
| * Merge branch 'rework/console-list-lock' into for-linusPetr Mladek2023-01-192-15/+10
| |\
| | * tty: serial: kgdboc: fix mutex locking order for configure_kgdboc()John Ogness2023-01-162-15/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Several mutexes are taken while setting up console serial ports. In particular, the tty_port->mutex and @console_mutex are taken: serial_pnp_probe serial8250_register_8250_port uart_add_one_port (locks tty_port->mutex) uart_configure_port register_console (locks @console_mutex) In order to synchronize kgdb's tty_find_polling_driver() with register_console(), commit 6193bc90849a ("tty: serial: kgdboc: synchronize tty_find_polling_driver() and register_console()") takes the @console_mutex. However, this leads to the following call chain (with locking): platform_probe kgdboc_probe configure_kgdboc (locks @console_mutex) tty_find_polling_driver uart_poll_init (locks tty_port->mutex) uart_set_options This is clearly deadlock potential due to the reverse lock ordering. Since uart_set_options() requires holding @console_mutex in order to serialize early initialization of the serial-console lock, take the @console_mutex in uart_poll_init() instead of configure_kgdboc(). Since configure_kgdboc() was using @console_mutex for safe traversal of the console list, change it to use the SRCU iterator instead. Add comments to uart_set_options() kerneldoc mentioning that it requires holding @console_mutex (aka the console_list_lock). Fixes: 6193bc90849a ("tty: serial: kgdboc: synchronize tty_find_polling_driver() and register_console()") Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Reviewed-by: Petr Mladek <pmladek@suse.com> [pmladek@suse.com: Export console_srcu_read_lock_is_held() to fix build kgdboc as a module.] Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20230112161213.1434854-1-john.ogness@linutronix.de
* | | Merge tag 'tty-6.2-rc1' of ↵Linus Torvalds2022-12-1672-1088/+812
|\ \ \ | |/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial driver updates from Greg KH: "Here is the "big" set of tty/serial driver changes for 6.2-rc1. As in previous kernel releases, nothing big here at all, just some small incremental serial/tty layer cleanups and some individual driver additions and fixes. Highlights are: - serial helper macros from Jiri Slaby to reduce the amount of duplicated code in serial drivers - api cleanups and consolidations from Ilpo Järvinen in lots of serial drivers - the usual set of n_gsm fixes from Daniel Starke as that code gets exercised more - TIOCSTI is finally able to be disabled if requested (security hardening feature from Kees Cook) - fsl_lpuart driver fixes and features added - other small serial driver additions and fixes All of these have been in linux-next for a while with no reported problems" * tag 'tty-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (97 commits) serial: atmel: don't stop the transmitter when doing PIO serial: atmel: cleanup atmel_start+stop_tx() tty: serial: fsl_lpuart: switch to new dmaengine_terminate_* API serial: sunsab: Fix error handling in sunsab_init() serial: altera_uart: fix locking in polling mode serial: pch: Fix PCI device refcount leak in pch_request_dma() tty: serial: fsl_lpuart: Use pm_ptr() to avoid need to make pm __maybe_unused tty: serial: fsl_lpuart: Add runtime pm support tty: serial: fsl_lpuart: enable wakeup source for lpuart serdev: Replace poll loop by readx_poll_timeout() macro tty: synclink_gt: unwind actions in error path of net device open serial: stm32: move dma_request_chan() before clk_prepare_enable() dt-bindings: serial: xlnx,opb-uartlite: Drop 'contains' from 'xlnx,use-parity' serial: pl011: Do not clear RX FIFO & RX interrupt in unthrottle. serial: amba-pl011: avoid SBSA UART accessing DMACR register tty: serial: altera_jtaguart: remove struct altera_jtaguart tty: serial: altera_jtaguart: use uart_port::read_status_mask tty: serial: altera_jtaguart: remove unused altera_jtaguart::sigs tty: serial: altera_jtaguart: remove flag from altera_jtaguart_rx_chars() n_tty: Rename tail to old_tail in n_tty_read() ...
| * | serial: atmel: don't stop the transmitter when doing PIOJiri Slaby (SUSE)2022-11-231-10/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Writing ATMEL_US_TXDIS to ATMEL_US_CR makes the transmitter NOT to send the just queued character. This means when the character is last and uart calls ops->stop_tx(), the character is not sent at all. The usart datasheet is not much specific on this, it just says the transmitter is stopped. But apparently, the character is dropped. So we should stop the transmitter only for DMA and PDC transfers to not send any more characters. For PIO, this is unexpected and deviates from other drivers. In particular, the below referenced commit broke TX as it added a call to ->stop_tx() after the very last character written to the transmitter. So fix this by limiting the write of ATMEL_US_TXDIS to DMA transfers only. Even there, I don't know if it is correctly implemented. Are all the queued characters sent once ->start_tx() is called? Anyone tested flow control -- be it hard (RTSCTS) or the soft (XOFF/XON) one? Fixes: 2d141e683e9a ("tty: serial: use uart_port_tx() helper") 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@microchip.com> Cc: linux-arm-kernel@lists.infradead.org Reported-by: Michael Walle <michael@walle.cc> Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20221123082736.24566-2-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | serial: atmel: cleanup atmel_start+stop_tx()Jiri Slaby (SUSE)2022-11-231-7/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Define local variables holding information about whether pdc or dma is used in the HW. These are retested several times by calls to atmel_use_pdc_tx() and atmel_use_dma_tx(). So to make the code more readable, simply cache the values. This is also a preparatory patch for the next one (where is_pdc is used once more in atmel_stop_tx()). 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@microchip.com> Cc: linux-arm-kernel@lists.infradead.org Reported-by: Michael Walle <michael@walle.cc> Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20221123082736.24566-1-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | tty: serial: fsl_lpuart: switch to new dmaengine_terminate_* APISherry Sun2022-11-231-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | Convert dmaengine_terminate_all() calls to synchronous and asynchronous versions where appropriate. Signed-off-by: Sherry Sun <sherry.sun@nxp.com> Link: https://lore.kernel.org/r/20221123023619.30173-1-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | serial: sunsab: Fix error handling in sunsab_init()Yuan Can2022-11-231-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The sunsab_init() returns the platform_driver_register() directly without checking its return value, if platform_driver_register() failed, the allocated sunsab_ports is leaked. Fix by free sunsab_ports and set it to NULL when platform_driver_register() failed. Fixes: c4d37215a824 ("[SERIAL] sunsab: Convert to of_driver framework.") Signed-off-by: Yuan Can <yuancan@huawei.com> Link: https://lore.kernel.org/r/20221123061212.52593-1-yuancan@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | serial: altera_uart: fix locking in polling modeGabriel Somlo2022-11-231-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since altera_uart_interrupt() may also be called from a poll timer in "serving_softirq" context, use spin_[lock_irqsave|unlock_irqrestore] variants, which are appropriate for both softirq and hardware interrupt contexts. Fixes: 2f8b9c15cd88 ("altera_uart: Add support for polling mode (IRQ-less)") Signed-off-by: Gabriel Somlo <gsomlo@gmail.com> Link: https://lore.kernel.org/r/20221122200426.888349-1-gsomlo@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | serial: pch: Fix PCI device refcount leak in pch_request_dma()Xiongfeng Wang2022-11-221-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As comment of pci_get_slot() says, it returns a pci_device with its refcount increased. The caller must decrement the reference count by calling pci_dev_put(). Since 'dma_dev' is only used to filter the channel in filter(), we can call pci_dev_put() before exiting from pch_request_dma(). Add the missing pci_dev_put() for the normal and error path. Fixes: 3c6a483275f4 ("Serial: EG20T: add PCH_UART driver") Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> Link: https://lore.kernel.org/r/20221122114559.27692-1-wangxiongfeng2@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | tty: serial: fsl_lpuart: Use pm_ptr() to avoid need to make pm __maybe_unusedSherry Sun2022-11-221-10/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | Use pm_ptr() to remove the need to mark the pm functions as __maybe_unused when the kernel is built without CONFIG_PM support. Signed-off-by: Sherry Sun <sherry.sun@nxp.com> Link: https://lore.kernel.org/r/20221110113859.8485-4-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | tty: serial: fsl_lpuart: Add runtime pm supportSherry Sun2022-11-221-0/+60
| | | | | | | | | | | | | | | | | | | | | | | | Add runtime pm support to manage the lpuart clock. Signed-off-by: Sherry Sun <sherry.sun@nxp.com> Link: https://lore.kernel.org/r/20221110113859.8485-3-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | tty: serial: fsl_lpuart: enable wakeup source for lpuartSherry Sun2022-11-221-81/+200
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | LPUART supports both synchronous wakeup and asynchronous wakeup(wakeup the system when the UART clocks are shut-off), the synchronous wakeup is configured by UARTCTRL_RIE interrupt, and the asynchronous wakeup is configured by UARTBAUD_RXEDGIE interrupt. Add lpuart_uport_is_active() to determine if the uart port needs to get into the suspend states, also add lpuart_suspend_noirq() and lpuart_resume_noirq() to enable and disable the wakeup irq bits if the uart port needs to be set as wakeup source. When use lpuart with DMA mode, it still needs to switch to the cpu mode in .suspend() that enable cpu interrupts RIE and RXEDGIE as wakeup source, after system resume back, needs to setup DMA again, .resume() will share the HW setup code with .startup(), so abstract the same code to the api like lpuart32_hw_setup(). Signed-off-by: Sherry Sun <sherry.sun@nxp.com> Link: https://lore.kernel.org/r/20221110113859.8485-2-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | serial: stm32: move dma_request_chan() before clk_prepare_enable()Valentin Caron2022-11-221-24/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If dma_request_chan() returns a PROBE_DEFER error, clk_disable_unprepare() will be called and USART clock will be disabled. But early console can be still active on the same USART. While moving dma_request_chan() before clk_prepare_enable(), the clock won't be taken in case of a DMA PROBE_DEFER error, and so it doesn't need to be disabled. Then USART is still clocked for early console. Fixes: a7770a4bfcf4 ("serial: stm32: defer probe for dma devices") Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Valentin Caron <valentin.caron@foss.st.com> Link: https://lore.kernel.org/r/20221118170602.1057863-1-valentin.caron@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | serial: pl011: Do not clear RX FIFO & RX interrupt in unthrottle.delisun2022-11-221-1/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Clearing the RX FIFO will cause data loss. Copy the pl011_enabl_interrupts implementation, and remove the clear interrupt and FIFO part of the code. Fixes: 211565b10099 ("serial: pl011: UPSTAT_AUTORTS requires .throttle/unthrottle") Signed-off-by: delisun <delisun@pateo.com.cn> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20221110020108.7700-1-delisun@pateo.com.cn Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | serial: amba-pl011: avoid SBSA UART accessing DMACR registerJiamei Xie2022-11-221-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Chapter "B Generic UART" in "ARM Server Base System Architecture" [1] documentation describes a generic UART interface. Such generic UART does not support DMA. In current code, sbsa_uart_pops and amba_pl011_pops share the same stop_rx operation, which will invoke pl011_dma_rx_stop, leading to an access of the DMACR register. This commit adds a using_rx_dma check in pl011_dma_rx_stop to avoid the access to DMACR register for SBSA UARTs which does not support DMA. When the kernel enables DMA engine with "CONFIG_DMA_ENGINE=y", Linux SBSA PL011 driver will access PL011 DMACR register in some functions. For most real SBSA Pl011 hardware implementations, the DMACR write behaviour will be ignored. So these DMACR operations will not cause obvious problems. But for some virtual SBSA PL011 hardware, like Xen virtual SBSA PL011 (vpl011) device, the behaviour might be different. Xen vpl011 emulation will inject a data abort to guest, when guest is accessing an unimplemented UART register. As Xen VPL011 is SBSA compatible, it will not implement DMACR register. So when Linux SBSA PL011 driver access DMACR register, it will get an unhandled data abort fault and the application will get a segmentation fault: Unhandled fault at 0xffffffc00944d048 Mem abort info: ESR = 0x96000000 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x00: ttbr address size fault Data abort info: ISV = 0, ISS = 0x00000000 CM = 0, WnR = 0 swapper pgtable: 4k pages, 39-bit VAs, pgdp=0000000020e2e000 [ffffffc00944d048] pgd=100000003ffff803, p4d=100000003ffff803, pud=100000003ffff803, pmd=100000003fffa803, pte=006800009c090f13 Internal error: ttbr address size fault: 96000000 [#1] PREEMPT SMP ... Call trace: pl011_stop_rx+0x70/0x80 tty_port_shutdown+0x7c/0xb4 tty_port_close+0x60/0xcc uart_close+0x34/0x8c tty_release+0x144/0x4c0 __fput+0x78/0x220 ____fput+0x1c/0x30 task_work_run+0x88/0xc0 do_notify_resume+0x8d0/0x123c el0_svc+0xa8/0xc0 el0t_64_sync_handler+0xa4/0x130 el0t_64_sync+0x1a0/0x1a4 Code: b9000083 b901f001 794038a0 8b000042 (b9000041) ---[ end trace 83dd93df15c3216f ]--- note: bootlogd[132] exited with preempt_count 1 /etc/rcS.d/S07bootlogd: line 47: 132 Segmentation fault start-stop-daemon This has been discussed in the Xen community, and we think it should fix this in Linux. See [2] for more information. [1] https://developer.arm.com/documentation/den0094/c/?lang=en [2] https://lists.xenproject.org/archives/html/xen-devel/2022-11/msg00543.html Fixes: 0dd1e247fd39 (drivers: PL011: add support for the ARM SBSA generic UART) Signed-off-by: Jiamei Xie <jiamei.xie@arm.com> Reviewed-by: Andre Przywara <andre.przywara@arm.com> Link: https://lore.kernel.org/r/20221117103237.86856-1-jiamei.xie@arm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | tty: serial: altera_jtaguart: remove struct altera_jtaguartJiri Slaby (SUSE)2022-11-221-20/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It contains only struct uart_port, so no need for another structure. Remove it and convert the rest to use struct uart_port directly. Cc: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Reviewed-by: Tobias Klauser <tklauser@distanz.ch> Link: https://lore.kernel.org/r/20221115071724.5185-4-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | tty: serial: altera_jtaguart: use uart_port::read_status_maskJiri Slaby (SUSE)2022-11-221-25/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of self-defined struct altera_jtaguart::imr, use preexisting uart_port::read_status_mask. Note that imr was ulong. But there is no reason for that, its values are uints. And readl/writel's are used to read it/write to it. Cc: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Reviewed-by: Tobias Klauser <tklauser@distanz.ch> Link: https://lore.kernel.org/r/20221115071724.5185-3-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | tty: serial: altera_jtaguart: remove unused altera_jtaguart::sigsJiri Slaby (SUSE)2022-11-221-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Nothing uses struct altera_jtaguart::sigs. Remove it. Cc: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Reviewed-by: Tobias Klauser <tklauser@distanz.ch> Link: https://lore.kernel.org/r/20221115071724.5185-2-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | tty: serial: altera_jtaguart: remove flag from altera_jtaguart_rx_chars()Jiri Slaby (SUSE)2022-11-221-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | TTY_NORMAL is the only value it contains, so remove the variable and use the constant instead. Cc: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Reviewed-by: Tobias Klauser <tklauser@distanz.ch> Link: https://lore.kernel.org/r/20221115071724.5185-1-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | Merge 6.1-rc6 into tty-nextGreg Kroah-Hartman2022-11-228-58/+101
| |\ \ | | | | | | | | | | | | | | | | | | | | We need the tty/serial fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | serial: 8250: 8250_omap: Fix calculation of RS485 delaysLukas Wunner2022-11-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 801954d1210a ("serial: 8250: 8250_omap: Support native RS485") calculates RS485 delays from the baudrate. The baudrate is generated with either a 16x or 13x divisor. The divisor is set in the Mode Definition Register 1 (MDR1). The commit erroneously assumes that the register stores the divisor as a bitmask and uses a logical AND to differentiate between 16x and 13x divisors. However the divisor is really stored as a 3-bit mode (see lines 363ff in include/uapi/linux/serial_reg.h). The logical AND operation is performed with UART_OMAP_MDR1_16X_MODE, which is defined as 0x0 and hence yields false. So the commit always assumes a 13x divisor. Fix by using an equal comparison. This works because we never set any of the other 5 bits in the register. (They pertain to IrDA mode, which is not supported by the driver). Fixes: 801954d1210a ("serial: 8250: 8250_omap: Support native RS485") Link: https://lore.kernel.org/linux-serial/202211070440.8hWunFUN-lkp@intel.com/ Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/7d5b04da13d89b8708b9543a0b125f2b6062a77b.1667977259.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | serial: 8250_bcm7271: Fix error handling in brcmuart_init()Yuan Can2022-11-091-1/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A problem about 8250_bcm7271 create debugfs failed is triggered with the following log given: [ 324.516635] debugfs: Directory 'bcm7271-uart' with parent '/' already present! The reason is that brcmuart_init() returns platform_driver_register() directly without checking its return value, if platform_driver_register() failed, it returns without destroy the newly created debugfs, resulting the debugfs of 8250_bcm7271 can never be created later. brcmuart_init() debugfs_create_dir() # create debugfs directory platform_driver_register() driver_register() bus_add_driver() priv = kzalloc(...) # OOM happened # return without destroy debugfs directory Fix by removing debugfs when platform_driver_register() returns error. Fixes: 41a469482de2 ("serial: 8250: Add new 8250-core based Broadcom STB driver") Signed-off-by: Yuan Can <yuancan@huawei.com> Link: https://lore.kernel.org/r/20221109072110.117291-2-yuancan@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | serial: 8250_dma: Rearm DMA Rx if more data is pendingIlpo Järvinen2022-11-091-3/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When DMA Rx completes, the current behavior is to just exit the DMA completion handler without future actions. If the transfer is still on-going, UART will trigger an interrupt and that eventually rearms the DMA Rx. The extra interrupt round-trip has an inherent latency cost that increases the risk of FIFO overrun. In such situations, the latency margin tends to already be less due to FIFO not being empty. Add check into DMA Rx completion handler to detect if LSR has DR (Data Ready) still set. DR indicates there will be more characters pending and DMA Rx can be rearmed right away to handle them. Cc: Gilles BULOZ <gilles.buloz@kontron.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20221107102126.56481-1-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | serial: Fix a typo ("ignorning")Jonathan Neuschäfer2022-11-092-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix the two instances of this typo present in the MSM and VT8500 serial drivers. Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net> Reviewed-by: Mukesh Ojha <quic_mojha@quicinc.com> Acked-by: Konrad Dybcio <konrad.dybcio@somainline.org> Link: https://lore.kernel.org/r/20221104103719.2234098-1-j.neuschaefer@gmx.net Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | serial: 8250_core: Use str_enabled_disabled() helperAndy Shevchenko2022-11-031-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use str_enabled_disabled() helper instead of open coding the same. Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20221017171633.65275-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | tty: serial: imx: Handle RS485 DE signal active highMarek Vasut2022-11-031-6/+58
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The default polarity of RS485 DE signal is active high. This driver does not handle such case properly. Currently, when a pin is multiplexed as a UART CTS_B on boot, this pin is pulled HIGH by the i.MX UART CTS circuit, which activates DE signal on the RS485 transceiver and thus behave as if the RS485 was transmitting data, so the system blocks the RS485 bus when it starts and until user application takes over. This behavior is not OK. The problem consists of two separate parts. First, the i.MX UART IP requires UCR1 UARTEN and UCR2 RXEN to be set for UCR2 CTSC and CTS bits to have any effect. The UCR2 CTSC bit permits the driver to set CTS (RTS_B or RS485 DE signal) to either level sychronous to the internal UART IP clock. Compared to other options, like GPIO CTS control, this has the benefit of being synchronous to the UART IP clock and thus without glitches or bus delays. The reason for the CTS design is likely because when the Receiver is disabled, the UART IP can never indicate that it is ready to receive data by assering CTS signal, so the CTS is always pulled HIGH by default. When the port is closed by user space, imx_uart_stop_rx() clears UCR2 RXEN bit, and imx_uart_shutdown() clears UCR1 UARTEN bit. This disables UART Receiver and UART itself, and forces CTS signal HIGH, which leads to the RS485 bus being blocked because RS485 DE is incorrectly active. The proposed solution for this problem is to keep the Receiver running even after the port is closed, but in loopback mode. This disconnects the RX FIFO input from the RXD external signal, and since UCR2 TXEN is cleared, the UART Transmitter is disabled, so nothing can feed data in the RX FIFO. Because the Receiver is still enabled, the UCR2 CTSC and CTS bits still have effect and the CTS (RS485 DE) control is retained. Note that in case of RS485 DE signal active low, there is no problem and no special handling is necessary. The CTS signal defaults to HIGH, thus the RS485 is by default set to Receive and the bus is not blocked. Note that while there is the possibility to control CTS using GPIO with either CTS polarity, this has the downside of not being synchronous to the UART IP clock and thus glitchy and susceptible to slow DE switching. Second, on boot, before the UART driver probe callback is called, the driver core triggers pinctrl_init_done() and configures the IOMUXC to default state. At this point, UCR1 UARTEN and UCR2 RXEN are both still cleared, but UART CTS_B (RS485 DE) is configured as CTS function, thus the RTS signal is pulled HIGH by the UART IP CTS circuit. One part of the solution here is to enable UCR1 UARTEN and UCR2 RXEN and UTS loopback in this driver probe callback, thus unblocking the CTSC and CTS control early on. But this is still too late, since the pin control is already configured and CTS has been pulled HIGH for a short period of time. When Linux kernel boots and this driver is bound, the pin control is set to special "init" state if the state is available, and driver can switch the "default" state afterward when ready. This state can be used to set the CTS line as a GPIO in DT temporarily, and a GPIO hog can force such GPIO to LOW, thus keeping the RS485 DE line LOW early on boot. Once the driver takes over and UCR1 UARTEN and UCR2 RXEN and UTS loopback are all enabled, the driver can switch to "default" pin control state and control the CTS line as function instead. DT binding example is below: " &gpio6 { rts-init-hog { gpio-hog; gpios = <5 0>; output-low; line-name = "rs485-de"; }; }; &uart5 { /* DHCOM UART2 */ pinctrl-0 = <&pinctrl_uart5>; pinctrl-1 = <&pinctrl_uart5_init>; pinctrl-names = "default", "init"; ... }; pinctrl_uart5_init: uart5-init-grp { fsl,pins = < ... MX6QDL_PAD_CSI0_DAT19__GPIO6_IO05 0x30b1 >; }; pinctrl_uart5: uart5-grp { fsl,pins = < ... MX6QDL_PAD_CSI0_DAT19__UART5_CTS_B 0x30b1 >; }; " Tested-by: Christoph Niedermaier <cniedermaier@dh-electronics.com> Reviewed-by: Fabio Estevam <festevam@denx.de> Signed-off-by: Marek Vasut <marex@denx.de> Link: https://lore.kernel.org/r/20220929144400.13571-1-marex@denx.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | serial: 8250/ingenic: Add support for the JZ4750/JZ4755Siarhei Volkau2022-11-031-3/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | JZ4750/55/60 (but not JZ4760b) have an optional /2 divider between the EXT oscillator and some peripherals including UART, which will be enabled if using a 24 MHz oscillator, and disabled when using a 12 MHz oscillator. This behavior relies on hardware differences: most boards (if not all) with those SoCs have 12 or 24 MHz oscillators but many peripherals want 12Mhz to operate properly (AIC and USB-PHY at least). The 16MHz threshold looks arbitrary but used in vendor's bootloader code for enable the divider. The patch doesn't affect JZ4760's behavior as it is subject for another patchset with re-classification of all supported ingenic UARTs. Link: https://github.com/carlos-wong/uboot_jz4755/blob/master/cpu/mips/jz_serial.c#L158 Signed-off-by: Siarhei Volkau <lis8215@gmail.com> Link: https://lore.kernel.org/r/20221031184041.1338129-3-lis8215@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | serial: tegra: Read DMA status before terminatingKartik2022-11-031-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Read the DMA status before terminating the DMA, as doing so deletes the DMA desc. Also, to get the correct transfer status information, pause the DMA using dmaengine_pause() before reading the DMA status. Fixes: e9ea096dd225 ("serial: tegra: add serial driver") Reviewed-by: Jon Hunter <jonathanh@nvidia.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Acked-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Akhil R <akhilrajeev@nvidia.com> Signed-off-by: Kartik <kkartik@nvidia.com> Link: https://lore.kernel.org/r/1666105086-17326-1-git-send-email-kkartik@nvidia.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | serial: zs: Use uart_xmit_advance()Ilpo Järvinen2022-11-031-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Take advantage of the new uart_xmit_advance() helper. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20221019091151.6692-45-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | serial: xuartps: Use uart_xmit_advance()Ilpo Järvinen2022-11-031-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Take advantage of the new uart_xmit_advance() helper. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20221019091151.6692-44-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | serial: ucc_uart: Use uart_xmit_advance()Ilpo Järvinen2022-11-031-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Take advantage of the new uart_xmit_advance() helper. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20221019091151.6692-43-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | serial: uartlite: Use uart_xmit_advance()Ilpo Järvinen2022-11-031-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Take advantage of the new uart_xmit_advance() helper. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20221019091151.6692-42-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | serial: timbuart: Use uart_xmit_advance()Ilpo Järvinen2022-11-031-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Take advantage of the new uart_xmit_advance() helper. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20221019091151.6692-41-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | serial: sunzilog: Use uart_xmit_advance()Ilpo Järvinen2022-11-031-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Take advantage of the new uart_xmit_advance() helper. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20221019091151.6692-40-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | serial: sunsu: Use uart_xmit_advance()Ilpo Järvinen2022-11-031-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Take advantage of the new uart_xmit_advance() helper. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20221019091151.6692-39-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | serial: sunsab: Use uart_xmit_advance()Ilpo Järvinen2022-11-031-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Take advantage of the new uart_xmit_advance() helper. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20221019091151.6692-38-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 2024-07-19 19:40:49 +0000