From: Stefan Wahren stefan.wahren@i2se.com
[ Upstream commit dca5480ab7b77a889088ab7cac81934604510ac7 ]
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/... 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 Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/w1/slaves/w1_therm.c | 31 ++++++++++++++----------------- 1 file changed, 14 insertions(+), 17 deletions(-)
diff --git a/drivers/w1/slaves/w1_therm.c b/drivers/w1/slaves/w1_therm.c index 9cbeeb4923ecf..67d1cfbbb5f7f 100644 --- a/drivers/w1/slaves/w1_therm.c +++ b/drivers/w1/slaves/w1_therm.c @@ -1093,29 +1093,26 @@ 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);