diff options
| author | Ansuel Smith <ansuelsmth@gmail.com> | 2021-10-07 20:28:59 +0300 |
|---|---|---|
| committer | Daniel Lezcano <daniel.lezcano@linaro.org> | 2021-10-16 21:24:43 +0300 |
| commit | d012f9189fda0f3a1b303780ba0bbc7298d0d349 (patch) | |
| tree | 00fd50b0cff5cb15ff64552d31e276ff5243b0ff /drivers | |
| parent | 9e5a4fb8423081d0efbf165c71c7f4abdf5f918c (diff) | |
| download | linux-d012f9189fda0f3a1b303780ba0bbc7298d0d349.tar.xz | |
thermal/drivers/tsens: Add timeout to get_temp_tsens_valid
The function can loop and lock the system if for whatever reason the bit
for the target sensor is NEVER valid. This is the case if a sensor is
disabled by the factory and the valid bit is never reported as actually
valid. Add a timeout check and exit if a timeout occurs. As this is
a very rare condition, handle the timeout only if the first read fails.
While at it also rework the function to improve readability and convert
to poll_timeout generic macro.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20211007172859.583-1-ansuelsmth@gmail.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/thermal/qcom/tsens.c | 29 |
1 files changed, 14 insertions, 15 deletions
diff --git a/drivers/thermal/qcom/tsens.c b/drivers/thermal/qcom/tsens.c index b1162e566a70..99a8d9f3e03c 100644 --- a/drivers/thermal/qcom/tsens.c +++ b/drivers/thermal/qcom/tsens.c @@ -603,22 +603,21 @@ int get_temp_tsens_valid(const struct tsens_sensor *s, int *temp) int ret; /* VER_0 doesn't have VALID bit */ - if (tsens_version(priv) >= VER_0_1) { - ret = regmap_field_read(priv->rf[valid_idx], &valid); - if (ret) - return ret; - while (!valid) { - /* Valid bit is 0 for 6 AHB clock cycles. - * At 19.2MHz, 1 AHB clock is ~60ns. - * We should enter this loop very, very rarely. - */ - ndelay(400); - ret = regmap_field_read(priv->rf[valid_idx], &valid); - if (ret) - return ret; - } - } + if (tsens_version(priv) == VER_0) + goto get_temp; + + /* Valid bit is 0 for 6 AHB clock cycles. + * At 19.2MHz, 1 AHB clock is ~60ns. + * We should enter this loop very, very rarely. + * Wait 1 us since it's the min of poll_timeout macro. + * Old value was 400 ns. + */ + ret = regmap_field_read_poll_timeout(priv->rf[valid_idx], valid, + valid, 1, 20 * USEC_PER_MSEC); + if (ret) + return ret; +get_temp: /* Valid bit is set, OK to read the temperature */ *temp = tsens_hw_to_mC(s, temp_idx); |