[PATCH 1/2] drm: omapdrm: dsi: fix-reference-leak-in dsi_runtime_get.

Zhang Qilong zhangqilong3 at huawei.com
Fri Nov 6 13:01:02 UTC 2020


pm_runtime_get_sync() will increment pm usage at first and it
will resume the device later. If runtime of the device has
error or device is in inaccessible state(or other error state),
resume operation will fail. If we do not call put operation to
decrease the reference, it will result in reference leak in
dsi_runtime_get. Moreover, this device cannot enter the idle
state and always stay busy or other non-idle state later. So we
should fix it through adding pm_runtime_put_noidle.

Fixes: 4600ea9c49cc4 ("drm: omapdrm: dsi: Store the struct device pointer in struct dsi_data")

Signed-off-by: Zhang Qilong <zhangqilong3 at huawei.com>
---
 drivers/gpu/drm/omapdrm/dss/dsi.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/omapdrm/dss/dsi.c b/drivers/gpu/drm/omapdrm/dss/dsi.c
index eeccf40bae41..f407d9c60ada 100644
--- a/drivers/gpu/drm/omapdrm/dss/dsi.c
+++ b/drivers/gpu/drm/omapdrm/dss/dsi.c
@@ -1112,8 +1112,12 @@ static int dsi_runtime_get(struct dsi_data *dsi)
 	DSSDBG("dsi_runtime_get\n");
 
 	r = pm_runtime_get_sync(dsi->dev);
-	WARN_ON(r < 0);
-	return r < 0 ? r : 0;
+	if (WARN_ON(r < 0)) {
+		pm_runtime_put_noidle(dsi->dev);
+		return r;
+	}
+
+	return 0;
 }
 
 static void dsi_runtime_put(struct dsi_data *dsi)
-- 
2.25.4



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