Romain Izard 93e1c8a638 usb: cdc-acm: fix race during wakeup blocking TX traffic ... When the kernel is compiled with preemption enabled, the URB completion handler can run in parallel with the work responsible for waking up the tty layer. If the URB handler sets the EVENT_TTY_WAKEUP bit during the call to tty_port_tty_wakeup() to signal that there is room for additional input, it will be cleared at the end of this call. As a result, TX traffic on the upper layer will be blocked. This can be seen with a kernel configured with CONFIG_PREEMPT, and a fast modem connected with PPP running over a USB CDC-ACM port. Use test_and_clear_bit() instead, which ensures that each wakeup requested by the URB completion code will trigger a call to tty_port_tty_wakeup(). Fixes: 1aba579f3c cdc-acm: handle read pipe errors Signed-off-by: Romain Izard <romain.izard.pro@gmail.com> Cc: stable <stable@vger.kernel.org> Acked-by: Oliver Neukum <oneukum@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2019-03-28 00:08:49 +09:00
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cdc-acm.c	usb: cdc-acm: fix race during wakeup blocking TX traffic	2019-03-28 00:08:49 +09:00
cdc-acm.h	cdc-acm: fix abnormal DATA RX issue for Mediatek Preloader.	2018-12-20 16:38:52 +01:00
cdc-wdm.c	cdc-wdm: pass return value of recover_from_urb_loss	2019-02-19 14:41:38 +01:00
Kconfig	USB: add missing SPDX lines to Kconfig and Makefiles	2019-01-22 09:08:17 +01:00
Makefile	USB: add SPDX identifiers to all remaining Makefiles	2017-11-07 15:53:48 +01:00
usblp.c	usb: usblp: use irqsave() in USB's complete callback	2018-06-28 19:36:06 +09:00
usbtmc.c	usb: usbtmc: uninitialized symbol 'actual' in usbtmc_ioctl_abort_bulk_in_tag	2018-09-28 15:12:08 +02:00