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author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-05-08 10:03:52 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-05-08 10:03:52 -0700 |
commit | 132d68d37d33f1d0b9c1f507c8b4d64c27ecec8a (patch) | |
tree | b3c05972e5579e1574873fe745fb1358c62a269c /drivers/usb/serial/generic.c | |
parent | 80f232121b69cc69a31ccb2b38c1665d770b0710 (diff) | |
parent | 3515468a87a47781f6af818773650513ff14656a (diff) | |
download | linux-stable-132d68d37d33f1d0b9c1f507c8b4d64c27ecec8a.tar.gz linux-stable-132d68d37d33f1d0b9c1f507c8b4d64c27ecec8a.tar.bz2 linux-stable-132d68d37d33f1d0b9c1f507c8b4d64c27ecec8a.zip |
Merge tag 'usb-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
Pull USB/PHY updates from Greg KH:
"Here is the big set of USB and PHY driver patches for 5.2-rc1
There is the usual set of:
- USB gadget updates
- PHY driver updates and additions
- USB serial driver updates and fixes
- typec updates and new chips supported
- mtu3 driver updates
- xhci driver updates
- other tiny driver updates
Nothing really interesting, just constant forward progress.
All of these have been in linux-next for a while with no reported
issues. The usb-gadget and usb-serial trees were merged a bit "late",
but both of them had been in linux-next before they got merged here
last Friday"
* tag 'usb-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (206 commits)
USB: serial: f81232: implement break control
USB: serial: f81232: add high baud rate support
USB: serial: f81232: clear overrun flag
USB: serial: f81232: fix interrupt worker not stop
usb: dwc3: Rename DWC3_DCTL_LPM_ERRATA
usb: dwc3: Fix default lpm_nyet_threshold value
usb: dwc3: debug: Print GET_STATUS(device) tracepoint
usb: dwc3: Do core validation early on probe
usb: dwc3: gadget: Set lpm_capable
usb: gadget: atmel: tie wake lock to running clock
usb: gadget: atmel: support USB suspend
usb: gadget: atmel_usba_udc: simplify setting of interrupt-enabled mask
dwc2: gadget: Fix completed transfer size calculation in DDMA
usb: dwc2: Set lpm mode parameters depend on HW configuration
usb: dwc2: Fix channel disable flow
usb: dwc2: Set actual frame number for completed ISOC transfer
usb: gadget: do not use __constant_cpu_to_le16
usb: dwc2: gadget: Increase descriptors count for ISOC's
usb: introduce usb_ep_type_string() function
usb: dwc3: move synchronize_irq() out of the spinlock protected block
...
Diffstat (limited to 'drivers/usb/serial/generic.c')
-rw-r--r-- | drivers/usb/serial/generic.c | 76 |
1 files changed, 41 insertions, 35 deletions
diff --git a/drivers/usb/serial/generic.c b/drivers/usb/serial/generic.c index 2274d9625f63..1be8bea372a2 100644 --- a/drivers/usb/serial/generic.c +++ b/drivers/usb/serial/generic.c @@ -106,12 +106,8 @@ void usb_serial_generic_deregister(void) int usb_serial_generic_open(struct tty_struct *tty, struct usb_serial_port *port) { int result = 0; - unsigned long flags; - spin_lock_irqsave(&port->lock, flags); - port->throttled = 0; - port->throttle_req = 0; - spin_unlock_irqrestore(&port->lock, flags); + clear_bit(USB_SERIAL_THROTTLED, &port->flags); if (port->bulk_in_size) result = usb_serial_generic_submit_read_urbs(port, GFP_KERNEL); @@ -375,7 +371,7 @@ void usb_serial_generic_read_bulk_callback(struct urb *urb) { struct usb_serial_port *port = urb->context; unsigned char *data = urb->transfer_buffer; - unsigned long flags; + bool stopped = false; int status = urb->status; int i; @@ -383,42 +379,55 @@ void usb_serial_generic_read_bulk_callback(struct urb *urb) if (urb == port->read_urbs[i]) break; } - set_bit(i, &port->read_urbs_free); dev_dbg(&port->dev, "%s - urb %d, len %d\n", __func__, i, urb->actual_length); switch (status) { case 0: + usb_serial_debug_data(&port->dev, __func__, urb->actual_length, + data); + port->serial->type->process_read_urb(urb); break; case -ENOENT: case -ECONNRESET: case -ESHUTDOWN: dev_dbg(&port->dev, "%s - urb stopped: %d\n", __func__, status); - return; + stopped = true; + break; case -EPIPE: dev_err(&port->dev, "%s - urb stopped: %d\n", __func__, status); - return; + stopped = true; + break; default: dev_dbg(&port->dev, "%s - nonzero urb status: %d\n", __func__, status); - goto resubmit; + break; } - usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data); - port->serial->type->process_read_urb(urb); + /* + * Make sure URB processing is done before marking as free to avoid + * racing with unthrottle() on another CPU. Matches the barriers + * implied by the test_and_clear_bit() in + * usb_serial_generic_submit_read_urb(). + */ + smp_mb__before_atomic(); + set_bit(i, &port->read_urbs_free); + /* + * Make sure URB is marked as free before checking the throttled flag + * to avoid racing with unthrottle() on another CPU. Matches the + * smp_mb() in unthrottle(). + */ + smp_mb__after_atomic(); -resubmit: - /* Throttle the device if requested by tty */ - spin_lock_irqsave(&port->lock, flags); - port->throttled = port->throttle_req; - if (!port->throttled) { - spin_unlock_irqrestore(&port->lock, flags); - usb_serial_generic_submit_read_urb(port, i, GFP_ATOMIC); - } else { - spin_unlock_irqrestore(&port->lock, flags); - } + if (stopped) + return; + + if (test_bit(USB_SERIAL_THROTTLED, &port->flags)) + return; + + usb_serial_generic_submit_read_urb(port, i, GFP_ATOMIC); } EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback); @@ -454,10 +463,9 @@ void usb_serial_generic_write_bulk_callback(struct urb *urb) default: dev_err_console(port, "%s - nonzero urb status: %d\n", __func__, status); - goto resubmit; + break; } -resubmit: usb_serial_generic_write_start(port, GFP_ATOMIC); usb_serial_port_softint(port); } @@ -466,26 +474,24 @@ EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback); void usb_serial_generic_throttle(struct tty_struct *tty) { struct usb_serial_port *port = tty->driver_data; - unsigned long flags; - spin_lock_irqsave(&port->lock, flags); - port->throttle_req = 1; - spin_unlock_irqrestore(&port->lock, flags); + set_bit(USB_SERIAL_THROTTLED, &port->flags); } EXPORT_SYMBOL_GPL(usb_serial_generic_throttle); void usb_serial_generic_unthrottle(struct tty_struct *tty) { struct usb_serial_port *port = tty->driver_data; - int was_throttled; - spin_lock_irq(&port->lock); - was_throttled = port->throttled; - port->throttled = port->throttle_req = 0; - spin_unlock_irq(&port->lock); + clear_bit(USB_SERIAL_THROTTLED, &port->flags); + + /* + * Matches the smp_mb__after_atomic() in + * usb_serial_generic_read_bulk_callback(). + */ + smp_mb(); - if (was_throttled) - usb_serial_generic_submit_read_urbs(port, GFP_KERNEL); + usb_serial_generic_submit_read_urbs(port, GFP_KERNEL); } EXPORT_SYMBOL_GPL(usb_serial_generic_unthrottle); |