Subject: [PATCH 13/23] mmc: sdhci-esdhc-imx: restore watermark level setting after resume

From: [email-masked] (Adrian Hunter)
Date: Tue, 10 May 2016 12:30:16 +0300

On 15/04/16 20:29, Dong Aisheng wrote:
> Currently, we config the watermark_level register only in probe.
> This will cause the mmc write operation timeout issue after system
> resume back in LPSR mode. Because in LPSR mode, after system resume
> back, the watermark_level register(0x44) changes to 0x08000880, which
> set the write watermark level as 0, and set the read watermark level
> as 128. This value is incorrect.
> 
> This patch restores the setting of watermark level register after
> system resume back.

In sdhci_esdhc_imx_probe() the watermark setting is conditional on
esdhc_is_usdhc(imx_data), but in the resume it is not.  Is that intended?
If so, maybe explain that in the commit message.

Might be worth pulling out the constant 0x10401040 and #defining it since it
is used in more than one place too.

> 
> Signed-off-by: Dong Aisheng <[email-masked]>
> ---
>  drivers/mmc/host/sdhci-esdhc-imx.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
> index 6fef6bc..4c28fbb 100644
> --- a/drivers/mmc/host/sdhci-esdhc-imx.c
> +++ b/drivers/mmc/host/sdhci-esdhc-imx.c
> @@ -1261,6 +1261,11 @@ static int sdhci_esdhc_suspend(struct device *dev)
>  
>  static int sdhci_esdhc_resume(struct device *dev)
>  {
> +	struct sdhci_host *host = dev_get_drvdata(dev);
> +
> +	/* restore watermark setting in case it's lost in low power mode */
> +	writel(0x10401040, host->ioaddr + ESDHC_WTMK_LVL);
> +
>  	return sdhci_pltfm_resume(dev);
>  }
>  
>