| Message ID | 20221214131617.2447-5-johan+linaro@kernel.org |
|---|---|
| State | New |
| Headers | show |
| Series | thermal: fix locking regressions in linux-next | expand |
diff --git a/drivers/thermal/qcom/qcom-spmi-temp-alarm.c b/drivers/thermal/qcom/qcom-spmi-temp-alarm.c index bfaec74f13b2..e2429676d0d2 100644 --- a/drivers/thermal/qcom/qcom-spmi-temp-alarm.c +++ b/drivers/thermal/qcom/qcom-spmi-temp-alarm.c @@ -348,7 +348,12 @@ static int qpnp_tm_init(struct qpnp_tm_chip *chip) if (stage) chip->temp = qpnp_tm_decode_temp(chip, stage); + mutex_unlock(&chip->lock); + crit_temp = qpnp_tm_get_critical_trip_temp(chip); + + mutex_lock(&chip->lock); + ret = qpnp_tm_update_critical_trip_temp(chip, crit_temp); if (ret < 0) goto out;
The thermal-zone-device lock is held by core when setting trip points and the driver takes its chip lock in the corresponding callback. Fetching the thermal trip points using thermal_zone_get_trip() also involves taking the thermal-zone-device lock, which means that the chip lock can not be held when doing so. Drop the chip lock temporarily during probe to avoid the lock inversion that was detected by lockdep: ====================================================== WARNING: possible circular locking dependency detected 6.1.0-next-20221213 #122 Not tainted ------------------------------------------------------ systemd-udevd/264 is trying to acquire lock: ffff741e444a0920 (&chip->lock){+.+.}-{3:3}, at: qpnp_tm_get_temp+0xb4/0x1b0 [qcom_spmi_temp_alarm] but task is already holding lock: ffff741e44341618 (&tz->lock){+.+.}-{3:3}, at: thermal_zone_device_update+0x2c/0x70 which lock already depends on the new lock. Fixes: 78c3e2429be8 ("thermal/drivers/qcom: Use generic thermal_zone_get_trip() function") Signed-off-by: Johan Hovold <johan+linaro@kernel.org> --- drivers/thermal/qcom/qcom-spmi-temp-alarm.c | 5 +++++ 1 file changed, 5 insertions(+)