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| author | Heiner Kallweit <hkallweit1@gmail.com> | 2021-06-06 15:55:55 +0200 |
|---|---|---|
| committer | Wolfram Sang <wsa@kernel.org> | 2021-06-20 22:58:58 +0200 |
| commit | 065b6211a87746e196b56759a70c7851418dd741 (patch) | |
| tree | f02f40e128b5dafd8df9b6a885e84bc9ad31009b /drivers/i2c | |
| parent | Linux 5.13-rc6 (diff) | |
| download | linux-065b6211a87746e196b56759a70c7851418dd741.tar.xz linux-065b6211a87746e196b56759a70c7851418dd741.zip | |
i2c: i801: Ensure that SMBHSTSTS_INUSE_STS is cleared when leaving i801_access
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>
Diffstat (limited to 'drivers/i2c')
| -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); |