[PATCH 6.4 586/800] soundwire: qcom: fix unbalanced pm_runtime_put()

Greg Kroah-Hartman
2023-07-16T20:20:17Z

From: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

[ Upstream commit 9f9914b178a7935d2d94ee3e1bf55f2b42b18528 ]

This reverts commit 57ed510b0547 ("soundwire: qcom: use
pm_runtime_resume_and_get()") which introduced unbalanced
pm_runtime_put(), when device did not have runtime PM enabled.

If pm_runtime_resume_and_get() failed with -EACCES, the driver continued
execution and finally called pm_runtime_put_autosuspend(). Since
pm_runtime_resume_and_get() drops the usage counter on every error, this
lead to double decrement of that counter visible in certain debugfs
actions on unattached devices (still in reset state):

$ cat /sys/kernel/debug/soundwire/master-0-0/sdw:0:0217:f001:00:0/registers
qcom-soundwire 3210000.soundwire-controller: swrm_wait_for_wr_fifo_avail err write overflow
soundwire sdw-master-0: trf on Slave 1 failed:-5 read addr e36 count 1
soundwire sdw:0:0217:f001:00:0: Runtime PM usage count underflow!

Fixes: 57ed510b0547 ("soundwire: qcom: use pm_runtime_resume_and_get()")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20230517163750.997629-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/soundwire/qcom.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/soundwire/qcom.c b/drivers/soundwire/qcom.c
index 7c75c6e3fab54..bd39e78788590 100644
--- a/drivers/soundwire/qcom.c
+++ b/drivers/soundwire/qcom.c
@@ -535,11 +535,12 @@ static irqreturn_t qcom_swrm_wake_irq_handler(int irq, void *dev_id)
struct qcom_swrm_ctrl *ctrl = dev_id;
int ret;

- ret = pm_runtime_resume_and_get(ctrl->dev);
+ ret = pm_runtime_get_sync(ctrl->dev);
if (ret < 0 && ret != -EACCES) {
dev_err_ratelimited(ctrl->dev,
- "pm_runtime_resume_and_get failed in %s, ret %d\n",
+ "pm_runtime_get_sync failed in %s, ret %d\n",
__func__, ret);
+ pm_runtime_put_noidle(ctrl->dev);
return ret;
}

@@ -1090,11 +1091,12 @@ static int qcom_swrm_startup(struct snd_pcm_substream *substream,
struct snd_soc_dai *codec_dai;
int ret, i;

- ret = pm_runtime_resume_and_get(ctrl->dev);
+ ret = pm_runtime_get_sync(ctrl->dev);
if (ret < 0 && ret != -EACCES) {
dev_err_ratelimited(ctrl->dev,
- "pm_runtime_resume_and_get failed in %s, ret %d\n",
+ "pm_runtime_get_sync failed in %s, ret %d\n",
__func__, ret);
+ pm_runtime_put_noidle(ctrl->dev);
return ret;
}

@@ -1295,11 +1297,12 @@ static int swrm_reg_show(struct seq_file *s_file, void *data)
struct qcom_swrm_ctrl *ctrl = s_file->private;
int reg, reg_val, ret;

- ret = pm_runtime_resume_and_get(ctrl->dev);
+ ret = pm_runtime_get_sync(ctrl->dev);
if (ret < 0 && ret != -EACCES) {
dev_err_ratelimited(ctrl->dev,
- "pm_runtime_resume_and_get failed in %s, ret %d\n",
+ "pm_runtime_get_sync failed in %s, ret %d\n",
__func__, ret);
+ pm_runtime_put_noidle(ctrl->dev);
return ret;
}

--
2.39.2