On Fri, Aug 10, 2018 at 02:27:14PM +0200, Hans de Goede wrote:
> acpi_gsb_i2c_write_bytes() returns i2c_transfer()'s return value, which
> is the number of transfers executed on success, so 1.
>
> The ACPI code expects us to store 0 in gsb->status for success, not 1.
>
> Specifically this breaks the following code in the Thinkpad 8 DSDT:
>
> ECWR = I2CW = ECWR /* \_SB_.I2C1.BAT0.ECWR */
> If ((ECST == Zero))
> {
> ECRD = I2CR /* \_SB_.I2C1.I2CR */
> }
>
> Before this commit we set ECST to 1, causing the read to never happen
> breaking battery monitoring on the Thinkpad 8. Note the Thinkpad 8 also
> has some unrelated issues where i2c transfers are unreliable.
>
> This commit sets status to 0 if it was bigger then 0 (so success),
> mirroring the multi-byte read path, fixing this.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Acked-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
