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[1/2] soundwire: qcom: fix unbalanced pm_runtime_put()

Message ID 20230517163750.997629-1-krzysztof.kozlowski@linaro.org
State Accepted
Commit 9f9914b178a7935d2d94ee3e1bf55f2b42b18528
Headers show
Series [1/2] soundwire: qcom: fix unbalanced pm_runtime_put() | expand

Commit Message

Krzysztof Kozlowski May 17, 2023, 4:37 p.m. UTC 
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>
---
 drivers/soundwire/qcom.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

Comments

Vinod Koul May 29, 2023, 5:20 a.m. UTC | #1 
On 17-05-23, 18:37, Krzysztof Kozlowski wrote:
> 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):

Applied, thanks
diff mbox series

Patch

diff --git a/drivers/soundwire/qcom.c b/drivers/soundwire/qcom.c
index aad5942e5980..f442280af9d3 100644
--- a/drivers/soundwire/qcom.c
+++ b/drivers/soundwire/qcom.c
@@ -614,11 +614,12 @@  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;
 	}
 
@@ -1197,11 +1198,12 @@  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;
 	}
 
@@ -1402,11 +1404,12 @@  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;
 	}