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    Subject[PATCH AUTOSEL 5.13 08/85] media: am437x: fix pm_runtime_get_sync() usage count
    Date
    From: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

    [ Upstream commit c41e02493334985cca1a22efd5ca962ce3abb061 ]

    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().

    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/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);

    --
    2.30.2
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