diff options
| author | Heiner Kallweit <hkallweit1@gmail.com> | 2021-06-06 15:55:55 +0200 |
|---|---|---|
| committer | Sasha Levin <sashal@kernel.org> | 2021-06-30 08:47:02 -0400 |
| commit | 5079a0fcda66ced207ea1b175ce725b36a2d0b11 (patch) | |
| tree | b382464a4a96927842be668eb092ee8dc49aca61 /drivers | |
| parent | 39eb61208e9d54d5aa1b1820b23c1c41bf2851ac (diff) | |
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>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/i2c/busses/i2c-i801.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c index f9e1c2ceaac0..04a1e38f2a6f 100644 --- a/drivers/i2c/busses/i2c-i801.c +++ b/drivers/i2c/busses/i2c-i801.c @@ -978,6 +978,9 @@ static s32 i801_access(struct i2c_adapter *adap, u16 addr, } out: + /* Unlock the SMBus device for use by BIOS/ACPI */ + outb_p(SMBHSTSTS_INUSE_STS, SMBHSTSTS(priv)); + pm_runtime_mark_last_busy(&priv->pci_dev->dev); pm_runtime_put_autosuspend(&priv->pci_dev->dev); mutex_unlock(&priv->acpi_lock); |