| Message ID | d012221b-9a44-eb77-f7c2-4e498ef5f933@gmail.com |
|---|---|
| State | Accepted |
| Commit | 065b6211a87746e196b56759a70c7851418dd741 |
| Headers | show |
| Series | i2c: i801: Ensure that SMBHSTSTS_INUSE_STS is cleared when leaving i801_access | expand |
On Sun, Jun 06, 2021 at 03:41:03PM +0200, Heiner Kallweit wrote: > 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> > --- > drivers/i2c/busses/i2c-i801.c | 3 +++ > 1 file changed, 3 insertions(+) > <formletter> This is not the correct way to submit patches for inclusion in the stable kernel tree. Please read: https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html for how to do this properly. </formletter>
diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c index c7d96cf5e..ab3470e77 100644 --- a/drivers/i2c/busses/i2c-i801.c +++ b/drivers/i2c/busses/i2c-i801.c @@ -948,6 +948,9 @@ 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);
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> --- drivers/i2c/busses/i2c-i801.c | 3 +++ 1 file changed, 3 insertions(+)