Re: [PATCH 16/25] media: am437x: fix pm_runtime_get_sync() usage count
From: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
Date: 2021-05-05 12:34:02
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On Wed, 5 May 2021 11:42:06 +0200 Mauro Carvalho Chehab [off-list ref] wrote:
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.
While here, ensure that the driver will check if PM runtime
resumed at vpfe_initialize_device().
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
quoted hunk ↗ jump to hunk
--- drivers/media/platform/am437x/am437x-vpfe.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-)diff --git a/drivers/media/platform/am437x/am437x-vpfe.c b/drivers/media/platform/am437x/am437x-vpfe.c index 6cdc77dda0e4..1c9cb9e05fdf 100644 --- a/drivers/media/platform/am437x/am437x-vpfe.c +++ b/drivers/media/platform/am437x/am437x-vpfe.c@@ -1021,7 +1021,9 @@ static int vpfe_initialize_device(struct vpfe_device *vpfe) if (ret) return ret; - pm_runtime_get_sync(vpfe->pdev); + ret = pm_runtime_resume_and_get(vpfe->pdev); + if (ret < 0) + return ret; vpfe_config_enable(&vpfe->ccdc, 1);@@ -2443,7 +2445,11 @@ static int vpfe_probe(struct platform_device *pdev) pm_runtime_enable(&pdev->dev); /* for now just enable it here instead of waiting for the open */ - pm_runtime_get_sync(&pdev->dev); + ret = pm_runtime_resume_and_get(&pdev->dev); + if (ret < 0) { + vpfe_err(vpfe, "Unable to resume device.\n"); + goto probe_out_v4l2_unregister; + } vpfe_ccdc_config_defaults(ccdc);@@ -2530,6 +2536,11 @@ static int vpfe_suspend(struct device *dev) /* only do full suspend if streaming has started */ if (vb2_start_streaming_called(&vpfe->buffer_queue)) { + /* + * ignore RPM resume errors here, as it is already too late. + * A check like that should happen earlier, either at + * open() or just before start streaming. + */ pm_runtime_get_sync(dev); vpfe_config_enable(ccdc, 1);