Thread (73 messages) 73 messages, 9 authors, 2021-09-13
STALE1770d

[PATCH 13/25] media: rcar_fdp1: fix pm_runtime_get_sync() usage count

From: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Date: 2021-05-05 09:42:52
Also in: linux-renesas-soc, lkml
Subsystem: media input infrastructure (v4l/dvb), the rest · Maintainers: Mauro Carvalho Chehab, Linus Torvalds

The pm_runtime_get_sync() internally increments the
dev->power.usage_count without decrementing it, even on errors.
Replace it by the new pm_runtime_resume_and_get(), introduced by:
commit dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
in order to properly decrement the usage counter, avoiding
a potential PM usage counter leak.

Also, right now, the driver is ignoring any troubles when
trying to do PM resume. So, add the proper error handling
for the code.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
---
 drivers/media/platform/rcar_fdp1.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/drivers/media/platform/rcar_fdp1.c b/drivers/media/platform/rcar_fdp1.c
index d26413fa5205..89aac60066d9 100644
--- a/drivers/media/platform/rcar_fdp1.c
+++ b/drivers/media/platform/rcar_fdp1.c
@@ -2135,7 +2135,9 @@ static int fdp1_open(struct file *file)
 	}
 
 	/* Perform any power management required */
-	pm_runtime_get_sync(fdp1->dev);
+	ret = pm_runtime_resume_and_get(fdp1->dev);
+	if (ret < 0)
+		goto error_pm;
 
 	v4l2_fh_add(&ctx->fh);
 
@@ -2145,6 +2147,8 @@ static int fdp1_open(struct file *file)
 	mutex_unlock(&fdp1->dev_mutex);
 	return 0;
 
+error_pm:
+       v4l2_m2m_ctx_release(ctx->fh.m2m_ctx);
 error_ctx:
 	v4l2_ctrl_handler_free(&ctx->hdl);
 	kfree(ctx);
@@ -2352,7 +2356,9 @@ static int fdp1_probe(struct platform_device *pdev)
 
 	/* Power up the cells to read HW */
 	pm_runtime_enable(&pdev->dev);
-	pm_runtime_get_sync(fdp1->dev);
+	ret = pm_runtime_resume_and_get(fdp1->dev);
+	if (ret < 0)
+		goto disable_pm;
 
 	hw_version = fdp1_read(fdp1, FD1_IP_INTDATA);
 	switch (hw_version) {
@@ -2381,6 +2387,9 @@ static int fdp1_probe(struct platform_device *pdev)
 
 	return 0;
 
+disable_pm:
+	pm_runtime_disable(fdp1->dev);
+
 release_m2m:
 	v4l2_m2m_release(fdp1->m2m_dev);
 
-- 
2.30.2
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