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Subject[PATCH AUTOSEL 4.19 04/31] media: sti/bdisp: fix pm_runtime_get_sync() usage count
Date
From: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

[ Upstream commit c44eac5b72e23c31eefc0e10a71d9650036b8341 ]

The pm_runtime_get_sync() internally increments the
dev->power.usage_count without decrementing it, even on errors.

The bdisp_start_streaming() doesn't take it into account, which
would unbalance PM usage counter at bdisp_stop_streaming().

The logic at bdisp_probe() is correct, but the best is to use
the same call along the driver.

So, 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.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/media/platform/sti/bdisp/bdisp-v4l2.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/media/platform/sti/bdisp/bdisp-v4l2.c b/drivers/media/platform/sti/bdisp/bdisp-v4l2.c
index 00f6e3f06dac..1fb04dc0f7d0 100644
--- a/drivers/media/platform/sti/bdisp/bdisp-v4l2.c
+++ b/drivers/media/platform/sti/bdisp/bdisp-v4l2.c
@@ -499,7 +499,7 @@ static int bdisp_start_streaming(struct vb2_queue *q, unsigned int count)
{
struct bdisp_ctx *ctx = q->drv_priv;
struct vb2_v4l2_buffer *buf;
- int ret = pm_runtime_get_sync(ctx->bdisp_dev->dev);
+ int ret = pm_runtime_resume_and_get(ctx->bdisp_dev->dev);

if (ret < 0) {
dev_err(ctx->bdisp_dev->dev, "failed to set runtime PM\n");
@@ -1368,10 +1368,10 @@ static int bdisp_probe(struct platform_device *pdev)

/* Power management */
pm_runtime_enable(dev);
- ret = pm_runtime_get_sync(dev);
+ ret = pm_runtime_resume_and_get(dev);
if (ret < 0) {
dev_err(dev, "failed to set PM\n");
- goto err_pm;
+ goto err_remove;
}

/* Filters */
@@ -1399,6 +1399,7 @@ static int bdisp_probe(struct platform_device *pdev)
bdisp_hw_free_filters(bdisp->dev);
err_pm:
pm_runtime_put(dev);
+err_remove:
bdisp_debugfs_remove(bdisp);
err_v4l2:
v4l2_device_unregister(&bdisp->v4l2_dev);
--
2.30.2
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