Re: [PATCH V1] mmc: tegra: add sdhci tegra suspend and resume

From: Thierry Reding
Date: Tue Apr 02 2019 - 10:59:07 EST


On Mon, Apr 01, 2019 at 10:27:33PM -0700, Sowjanya Komatineni wrote:
> This patch adds suspend and resume PM ops for tegra SDHCI.
>
> Signed-off-by: Sowjanya Komatineni <skomatineni@xxxxxxxxxx>
> ---
> drivers/mmc/host/sdhci-tegra.c | 45 +++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 44 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
> index eafaaefab4a6..68263ea4a93e 100644
> --- a/drivers/mmc/host/sdhci-tegra.c
> +++ b/drivers/mmc/host/sdhci-tegra.c
> @@ -1611,11 +1611,54 @@ static int sdhci_tegra_remove(struct platform_device *pdev)
> return 0;
> }
>
> +#ifdef CONFIG_PM_SLEEP
> +static int sdhci_tegra_suspend(struct device *dev)
> +{
> + struct sdhci_host *host = dev_get_drvdata(dev);
> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> + int ret;
> +
> + if (host->mmc->caps2 & MMC_CAP2_CQE) {
> + ret = cqhci_suspend(host->mmc);
> + if (ret)
> + return ret;
> + }
> +
> + ret = sdhci_suspend_host(host);
> + if (ret)
> + return ret;
> +
> + clk_disable_unprepare(pltfm_host->clk);
> + return 0;
> +}
> +
> +static int sdhci_tegra_resume(struct device *dev)
> +{
> + struct sdhci_host *host = dev_get_drvdata(dev);
> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> + int ret;
> +
> + clk_prepare_enable(pltfm_host->clk);

You need to check this for errors here.

> +
> + ret = sdhci_resume_host(host);
> + if (ret)
> + return ret;

And clk_disable_unprepare() in case of failure.

> +
> + if (host->mmc->caps2 & MMC_CAP2_CQE)
> + return cqhci_resume(host->mmc);

Same here. Also make sure to sdhci_suspend_host() if cqhci_resume()
fails. It's probably best to have a standard error cleanup path for
this.

Thierry

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