platform_kernel-5.15/drivers/i2c
Martin Povišer 83a4c1080e i2c: pasemi: Wait for write xfers to finish
commit bd8963e602c77adc76dbbbfc3417c3cf14fed76b upstream.

Wait for completion of write transfers before returning from the driver.
At first sight it may seem advantageous to leave write transfers queued
for the controller to carry out on its own time, but there's a couple of
issues with it:

 * Driver doesn't check for FIFO space.

 * The queued writes can complete while the driver is in its I2C read
   transfer path which means it will get confused by the raising of
   XEN (the 'transaction ended' signal). This can cause a spurious
   ENODATA error due to premature reading of the MRXFIFO register.

Adding the wait fixes some unreliability issues with the driver. There's
some efficiency cost to it (especially with pasemi_smb_waitready doing
its polling), but that will be alleviated once the driver receives
interrupt support.

Fixes: beb58aa39e ("i2c: PA Semi SMBus driver")
Signed-off-by: Martin Povišer <povik+lin@cutebit.org>
Reviewed-by: Sven Peter <sven@svenpeter.dev>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-20 09:34:21 +02:00
..
algos i2c: algo: bit: use new macro to specifiy capabilities 2021-01-22 09:59:21 +01:00
busses i2c: pasemi: Wait for write xfers to finish 2022-04-20 09:34:21 +02:00
muxes i2c: mux: demux-pinctrl: do not deactivate a master that is not active 2022-04-08 14:23:42 +02:00
Kconfig i2c: add slave testunit driver 2020-09-21 11:02:17 +02:00
Makefile i2c: add slave testunit driver 2020-09-21 11:02:17 +02:00
i2c-boardinfo.c i2c: Remove support for dangling device properties 2021-04-10 21:43:02 +02:00
i2c-core-acpi.c i2c: acpi: fix resource leak in reconfiguration device addition 2021-10-02 08:38:43 +02:00
i2c-core-base.c Revert "i2c: core: support bus regulator controlling in adapter" 2022-01-11 15:35:15 +01:00
i2c-core-of.c i2c: use my kernel.org address from now on 2020-05-05 16:29:09 +02:00
i2c-core-slave.c i2c: slave: add sanity check when unregistering 2020-07-28 18:37:17 +02:00
i2c-core-smbus.c i2c: core-smbus: Expose PEC calculate function for generic use 2021-06-25 17:09:34 +02:00
i2c-core.h i2c: acpi: Remove dead code, i.e. i2c_acpi_match_device() 2020-08-25 09:22:09 +02:00
i2c-dev.c i2c: dev: check return value when calling dev_set_name() 2022-04-20 09:34:20 +02:00
i2c-mux.c i2c: mux: add sysfs header 2019-06-22 07:32:33 +02:00
i2c-slave-eeprom.c i2c: busses: Use fallthrough pseudo-keyword 2020-07-23 22:04:08 +02:00
i2c-slave-testunit.c i2c: testunit: add support for block process calls 2021-02-12 11:11:04 +01:00
i2c-smbus.c i2c: smbus: add core function handling SMBus host-notify 2020-09-09 10:38:28 +02:00
i2c-stub.c i2c: stub: remove definition of DEBUG 2021-01-17 13:00:10 +01:00