| Message ID | dbab81a4521f26538a9ac0c8af838c1ba987ab5a.1620207353.git.mchehab+huawei@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Fix some PM runtime issues at the media subsystem | expand |
On Wed, 5 May 2021 11:42:12 +0200 Mauro Carvalho Chehab <mchehab+huawei@kernel.org> wrote: > 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. > > Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > --- > 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 060ca85f64d5..85288da9d2ae 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"); > @@ -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 @@ 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); > v4l2_device_unregister(&bdisp->v4l2_dev); > err_clk:
diff --git a/drivers/media/platform/sti/bdisp/bdisp-v4l2.c b/drivers/media/platform/sti/bdisp/bdisp-v4l2.c index 060ca85f64d5..85288da9d2ae 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"); @@ -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 @@ 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); v4l2_device_unregister(&bdisp->v4l2_dev); err_clk:
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. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> --- drivers/media/platform/sti/bdisp/bdisp-v4l2.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)