From: Hans de Goede hdegoede@redhat.com
commit 21d90aaee8d5c2a097ef41f1430d97661233ecc6 upstream.
The battery on the 2nd hand Surface 3 which I recently bought appears to not have a serial number programmed in. This results in any I2C reads from the registers containing the serial number failing with an I2C NACK.
This was causing mshw0011_bix() to fail causing the battery readings to not work at all.
Ignore EREMOTEIO (I2C NACK) errors when retrieving the serial number and continue with an empty serial number to fix this.
Fixes: b1f81b496b0d ("platform/x86: surface3_power: MSHW0011 rev-eng implementation") BugLink: https://github.com/linux-surface/linux-surface/issues/608 Reviewed-by: Benjamin Tissoires benjamin.tissoires@redhat.com Reviewed-by: Maximilian Luz luzmaximilian@gmail.com Signed-off-by: Hans de Goede hdegoede@redhat.com Link: https://lore.kernel.org/r/20220224101848.7219-1-hdegoede@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/platform/x86/surface3_power.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-)
--- a/drivers/platform/x86/surface3_power.c +++ b/drivers/platform/x86/surface3_power.c @@ -233,14 +233,21 @@ static int mshw0011_bix(struct mshw0011_ } bix->last_full_charg_capacity = ret;
- /* get serial number */ + /* + * Get serial number, on some devices (with unofficial replacement + * battery?) reading any of the serial number range addresses gets + * nacked in this case just leave the serial number empty. + */ ret = i2c_smbus_read_i2c_block_data(client, MSHW0011_BAT0_REG_SERIAL_NO, sizeof(buf), buf); - if (ret != sizeof(buf)) { + if (ret == -EREMOTEIO) { + /* no serial number available */ + } else if (ret != sizeof(buf)) { dev_err(&client->dev, "Error reading serial no: %d\n", ret); return ret; + } else { + snprintf(bix->serial, ARRAY_SIZE(bix->serial), "%3pE%6pE", buf + 7, buf); } - snprintf(bix->serial, ARRAY_SIZE(bix->serial), "%3pE%6pE", buf + 7, buf);
/* get cycle count */ ret = i2c_smbus_read_word_data(client, MSHW0011_BAT0_REG_CYCLE_CNT);