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@vger.kernel.org Signed-off-by: Hans de Goede hdegoede@redhat.com
Acked-by: Mika Westerberg mika.westerberg@linux.intel.com