On 2/24/22 11:18, Hans de Goede wrote:
The battery on the 2nd hand Surface 3 which I recently bought appears to
not have a serial no programmed in. This results in any I2C reads from
the registers containing the serial no 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 no and
continue with an empty serial no to fix this.
Fixes: b1f81b496b0d ("platform/x86: surface3_power: MSHW0011 rev-eng implementation")
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Thanks for fixing this! This has been bugging us over at
https://github.com/linux-surface/linux-surface/issues/608.
Reviewed-by: Maximilian Luz <luzmaximilian@xxxxxxxxx>
---
drivers/platform/surface/surface3_power.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/drivers/platform/surface/surface3_power.c b/drivers/platform/surface/surface3_power.c
index abac3eec565e..b283bc9bb5fd 100644
--- a/drivers/platform/surface/surface3_power.c
+++ b/drivers/platform/surface/surface3_power.c
@@ -232,14 +232,21 @@ static int mshw0011_bix(struct mshw0011_data *cdata, struct bix *bix)
}
bix->last_full_charg_capacity = ret;
- /* get serial number */
+ /*
+ * get serial number, on some devices (with unofficial replacement
+ * battery?) reading any of the serial no range addresses gets nacked
+ * in this case just leave the serial no 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);
