linux/drivers/i2c
Simon Lindgren 6721f28a26 i2c: at91: Fix a race condition during signal handling in at91_do_twi_xfer.
There is a race condition in at91_do_twi_xfer when signals arrive.
If a signal is recieved while waiting for a transfer to complete
wait_for_completion_interruptible_timeout() will return -ERESTARTSYS.
This is not handled correctly resulting in interrupts still being
enabled and a transfer being in flight when we return.

Symptoms include a range of oopses and bus lockups. Oopses can happen
when the transfer completes because the interrupt handler will corrupt
the stack. If a new transfer is started before the interrupt fires
the controller will start a new transfer in the middle of the old one,
resulting in confused slaves and a locked bus.

To avoid this, use wait_for_completion_io_timeout instead so that we
don't have to deal with gracefully shutting down the transfer and
disabling the interrupts.

Signed-off-by: Simon Lindgren <simon@aqwary.com>
Acked-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
2014-09-02 14:29:20 +02:00
..
algos Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2014-01-29 19:56:20 -08:00
busses i2c: at91: Fix a race condition during signal handling in at91_do_twi_xfer. 2014-09-02 14:29:20 +02:00
muxes Merge branch 'i2c/for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2014-08-09 09:15:07 -07:00
i2c-acpi.c i2c: rework kernel config I2C_ACPI 2014-08-19 10:19:39 -05:00
i2c-boardinfo.c i2c: Update the FSF address 2012-03-26 21:47:19 +02:00
i2c-core.c Merge branch 'i2c/for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2014-08-09 09:15:07 -07:00
i2c-core.h i2c: Update the FSF address 2012-03-26 21:47:19 +02:00
i2c-dev.c i2c: i2c-dev: Create 'name' attribute automatically 2013-09-30 06:02:31 +02:00
i2c-mux.c i2c: mux: Inherit retry count and timeout from parent for muxed bus 2013-12-12 22:39:28 +01:00
i2c-smbus.c Update Jean Delvare's e-mail address 2014-01-29 20:40:08 +01:00
i2c-stub.c i2c: stub: Avoid an array overrun on I2C block transfers 2014-07-20 13:25:29 +02:00
Kconfig i2c: rework kernel config I2C_ACPI 2014-08-19 10:19:39 -05:00
Makefile i2c: rework kernel config I2C_ACPI 2014-08-19 10:19:39 -05:00