i2c: i801: Ensure that SMBHSTSTS_INUSE_STS is cleared when leaving i801_access
authorHeiner Kallweit <hkallweit1@gmail.com>
Sun, 6 Jun 2021 13:55:55 +0000 (15:55 +0200)
committerSasha Levin <sashal@kernel.org>
Wed, 30 Jun 2021 12:47:24 +0000 (08:47 -0400)
commit0221a5a4db46bcfd797edd92036028db2879c06c
tree669fbfb417fdd002887f0928339737f0f1cbc834
parent018d03fcf77a7e6a37503397f871095f7fd909ec
i2c: i801: Ensure that SMBHSTSTS_INUSE_STS is cleared when leaving i801_access

[ Upstream commit 065b6211a87746e196b56759a70c7851418dd741 ]

As explained in [0] currently we may leave SMBHSTSTS_INUSE_STS set,
thus potentially breaking ACPI/BIOS usage of the SMBUS device.

Seems patch [0] needs a little bit more of review effort, therefore
I'd suggest to apply a part of it as quick win. Just clearing
SMBHSTSTS_INUSE_STS when leaving i801_access() should fix the
referenced issue and leaves more time for discussing a more
sophisticated locking handling.

[0] https://www.spinics.net/lists/linux-i2c/msg51558.html

Fixes: 01590f361e94 ("i2c: i801: Instantiate SPD EEPROMs automatically")
Suggested-by: Hector Martin <marcan@marcan.st>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Hector Martin <marcan@marcan.st>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Tested-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/i2c/busses/i2c-i801.c