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| author | Stefan Wahren <stefan.wahren@i2se.com> | 2023-04-27 13:21:52 +0200 |
|---|---|---|
| committer | Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> | 2023-05-08 08:13:35 +0200 |
| commit | dca5480ab7b77a889088ab7cac81934604510ac7 (patch) | |
| tree | 2fd18ad52ee9970bde0dffede433377daeb78610 /drivers/w1 | |
| parent | ac9a78681b921877518763ba0e89202254349d1b (diff) | |
| download | linux-dca5480ab7b77a889088ab7cac81934604510ac7.tar.gz | |
w1: w1_therm: fix locking behavior in convert_t
The commit 67b392f7b8ed ("w1_therm: optimizing temperature read timings")
accidentially inverted the logic for lock handling of the bus mutex.
Before:
pullup -> release lock before sleep
no pullup -> release lock after sleep
After:
pullup -> release lock after sleep
no pullup -> release lock before sleep
This cause spurious measurements of 85 degree (powerup value) on the
Tarragon board with connected 1-w temperature sensor
(w1_therm.w1_strong_pull=0).
In the meantime a new feature for polling the conversion
completion has been integrated in these branches with
commit 021da53e65fd ("w1: w1_therm: Add sysfs entries to control
conversion time and driver features"). But this feature isn't
available for parasite power mode, so handle this separately.
Link: https://lore.kernel.org/regressions/2023042645-attentive-amends-7b0b@gregkh/T/
Fixes: 67b392f7b8ed ("w1_therm: optimizing temperature read timings")
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Link: https://lore.kernel.org/r/20230427112152.12313-1-stefan.wahren@i2se.com
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Diffstat (limited to 'drivers/w1')
| -rw-r--r-- | drivers/w1/slaves/w1_therm.c | 31 |
1 files changed, 14 insertions, 17 deletions
diff --git a/drivers/w1/slaves/w1_therm.c b/drivers/w1/slaves/w1_therm.c index 067692626cf07..99c58bd9d2df0 100644 --- a/drivers/w1/slaves/w1_therm.c +++ b/drivers/w1/slaves/w1_therm.c @@ -1159,29 +1159,26 @@ static int convert_t(struct w1_slave *sl, struct therm_info *info) w1_write_8(dev_master, W1_CONVERT_TEMP); - if (strong_pullup) { /*some device need pullup */ + if (SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) { + ret = w1_poll_completion(dev_master, W1_POLL_CONVERT_TEMP); + if (ret) { + dev_dbg(&sl->dev, "%s: Timeout\n", __func__); + goto mt_unlock; + } + mutex_unlock(&dev_master->bus_mutex); + } else if (!strong_pullup) { /*no device need pullup */ sleep_rem = msleep_interruptible(t_conv); if (sleep_rem != 0) { ret = -EINTR; goto mt_unlock; } mutex_unlock(&dev_master->bus_mutex); - } else { /*no device need pullup */ - if (SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) { - ret = w1_poll_completion(dev_master, W1_POLL_CONVERT_TEMP); - if (ret) { - dev_dbg(&sl->dev, "%s: Timeout\n", __func__); - goto mt_unlock; - } - mutex_unlock(&dev_master->bus_mutex); - } else { - /* Fixed delay */ - mutex_unlock(&dev_master->bus_mutex); - sleep_rem = msleep_interruptible(t_conv); - if (sleep_rem != 0) { - ret = -EINTR; - goto dec_refcnt; - } + } else { /*some device need pullup */ + mutex_unlock(&dev_master->bus_mutex); + sleep_rem = msleep_interruptible(t_conv); + if (sleep_rem != 0) { + ret = -EINTR; + goto dec_refcnt; } } ret = read_scratchpad(sl, info); |