Ahmed S. Darwish a9dc960c37 can: kvaser_usb: Fix tx queue start/stop race conditions ... A number of tx queue wake-up events went missing due to the outlined scenario below. Start state is a pool of 16 tx URBs, active tx_urbs count = 15, with the netdev tx queue open. CPU #1 [softirq] CPU #2 [softirq] start_xmit() tx_acknowledge() ................ ................ atomic_inc(&tx_urbs); if (atomic_read(&tx_urbs) >= 16) { --> atomic_dec(&tx_urbs); netif_wake_queue(); return; <-- netif_stop_queue(); } At the end, the correct state expected is a 15 tx_urbs count value with the tx queue state _open_. Due to the race, we get the same tx_urbs value but with the tx queue state _stopped_. The wake-up event is completely lost. Thus avoid hand-rolled concurrency mechanisms and use a proper lock for contexts and tx queue protection. Signed-off-by: Ahmed S. Darwish <ahmed.darwish@valeo.com> Cc: linux-stable <stable@vger.kernel.org> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>		2015-03-14 09:20:07 +01:00
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c_can
cc770
m_can
mscan
sja1000
softing
spi
usb	can: kvaser_usb: Fix tx queue start/stop race conditions	2015-03-14 09:20:07 +01:00
at91_can.c
bfin_can.c
dev.c
flexcan.c
grcan.c
janz-ican3.c
Kconfig	net: can: Enable xilinx driver for ARM64	2015-03-14 09:01:16 +01:00
led.c
Makefile
pch_can.c
rcar_can.c
slcan.c
ti_hecc.c
vcan.c
xilinx_can.c