Re: [PATCH v6 10/16] dmaengine: tegra-apb: Remove assumptions about unavailable runtime PM

Jon Hunter
2020-01-30T14:09:10Z

On 30/01/2020 04:37, Dmitry Osipenko wrote:
> The runtime PM is always available on all Tegra SoCs since the commit
> 40b2bb1b132a ("ARM: tegra: enforce PM requirement"), so there is no
> need to handle the case of unavailable RPM in the code anymore.
>
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
> drivers/dma/tegra20-apb-dma.c | 10 +---------
> 1 file changed, 1 insertion(+), 9 deletions(-)
>
> diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c
> index 7158bd3145c4..22b88ccff05d 100644
> --- a/drivers/dma/tegra20-apb-dma.c
> +++ b/drivers/dma/tegra20-apb-dma.c
> @@ -1429,11 +1429,8 @@ static int tegra_dma_probe(struct platform_device *pdev)
> spin_lock_init(&tdma->global_lock);
>
> pm_runtime_enable(&pdev->dev);
> - if (!pm_runtime_enabled(&pdev->dev))
> - ret = tegra_dma_runtime_resume(&pdev->dev);
> - else
> - ret = pm_runtime_get_sync(&pdev->dev);
>
> + ret = pm_runtime_get_sync(&pdev->dev);
> if (ret < 0)
> goto err_pm_disable;
>
> @@ -1546,8 +1543,6 @@ static int tegra_dma_probe(struct platform_device *pdev)
>
> err_pm_disable:
> pm_runtime_disable(&pdev->dev);
> - if (!pm_runtime_status_suspended(&pdev->dev))
> - tegra_dma_runtime_suspend(&pdev->dev);
>
> return ret;
> }
> @@ -1557,10 +1552,7 @@ static int tegra_dma_remove(struct platform_device *pdev)
> struct tegra_dma *tdma = platform_get_drvdata(pdev);
>
> dma_async_device_unregister(&tdma->dma_dev);
> -
> pm_runtime_disable(&pdev->dev);
> - if (!pm_runtime_status_suspended(&pdev->dev))
> - tegra_dma_runtime_suspend(&pdev->dev);
>
> return 0;
> }

I wonder if we need to make the pm_runtime_put a pm_runtime_put_sync or
call pm_runtime_barrier() here, to ensure it has called the callback
when freeing the channel? Otherwise this is fine.

Jon

--
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