media: am437x: fix pm_runtime_get_sync() usage count

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>

diff --git a/drivers/media/platform/am437x/am437x-vpfe.c b/drivers/media/platform/am437x/am437x-vpfe.c
index 6cdc77d..1c9cb9e 100644 (file)
--- 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);