media: sti/bdisp: fix pm_runtime_get_sync() usage count

[ 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>

diff --git a/drivers/media/platform/sti/bdisp/bdisp-v4l2.c b/drivers/media/platform/sti/bdisp/bdisp-v4l2.c
index a55ddf8d185d5208a517da78b3d70b13ede93d39..16a097f93b42325339df4c79d3d2843c5d4614e2 100644 (file)
--- 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");
@@ -1364,10 +1364,10 @@ 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 */
@@ -1395,6 +1395,7 @@ err_filter:
        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);