linux-kernel - [PATCH 2/2] soundwire: debugfs: fix unbalanced pm_runtime

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Date:   Wed, 17 May 2023 18:37:50 +0200
From:   Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
To:     Vinod Koul <vkoul@...nel.org>,
        Bard Liao <yung-chuan.liao@...ux.intel.com>,
        Pierre-Louis Bossart <pierre-louis.bossart@...ux.intel.com>,
        Sanyog Kale <sanyog.r.kale@...el.com>,
        Andy Gross <agross@...nel.org>,
        Bjorn Andersson <andersson@...nel.org>,
        Konrad Dybcio <konrad.dybcio@...aro.org>,
        Péter Ujfalusi <peter.ujfalusi@...ux.intel.com>,
        Srinivas Kandagatla <srinivas.kandagatla@...aro.org>,
        Charles Keepax <ckeepax@...nsource.cirrus.com>,
        alsa-devel@...a-project.org, linux-kernel@...r.kernel.org,
        linux-arm-msm@...r.kernel.org
Cc:     Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
Subject: [PATCH 2/2] soundwire: debugfs: fix unbalanced pm_runtime_put()

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.

Fixes: b275bf45ba1d ("soundwire: debugfs: Switch to sdw_read_no_pm")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
---
 drivers/soundwire/debugfs.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/soundwire/debugfs.c b/drivers/soundwire/debugfs.c
index dea782e0edc4..c3a1a359ee5c 100644
--- a/drivers/soundwire/debugfs.c
+++ b/drivers/soundwire/debugfs.c
@@ -56,8 +56,9 @@ static int sdw_slave_reg_show(struct seq_file *s_file, void *data)
 	if (!buf)
 		return -ENOMEM;
 
-	ret = pm_runtime_resume_and_get(&slave->dev);
+	ret = pm_runtime_get_sync(&slave->dev);
 	if (ret < 0 && ret != -EACCES) {
+		pm_runtime_put_noidle(&slave->dev);
 		kfree(buf);
 		return ret;
 	}
-- 
2.34.1