Re: [PATCH v10 3/6] mmc: core: Add option to keep an eMMC powered on at system suspend

[Shawn Lin <shawn.lin@linux.dev>]

在 2026/10/27 星期二 22:40, Ulf Hansson 写道:
> The DT property keep-power-in-suspend, allows us to specify whether the
> platform is capable of keeping the power to the card during system suspend.
> Up until now, this has been restricted to be used for SDIO cards only, but
> let's add the initial support to allow this for eMMC too.
> 

Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com>

> Signed-off-by: Ulf Hansson <ulf.hansson@oss.qualcomm.com>
> ---
>   drivers/mmc/core/mmc.c | 24 +++++++++++++++++++++++-
>   1 file changed, 23 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
> index a02b04938e1a..c936272bcd81 100644
> --- a/drivers/mmc/core/mmc.c
> +++ b/drivers/mmc/core/mmc.c
> @@ -38,6 +38,7 @@ enum mmc_poweroff_type {
>   	MMC_POWEROFF_SHUTDOWN,
>   	MMC_POWEROFF_UNDERVOLTAGE,
>   	MMC_POWEROFF_UNBIND,
> +	MMC_NO_POWEROFF_SUSPEND,
>   };
>   
>   static const unsigned int tran_exp[] = {
> @@ -2157,6 +2158,15 @@ static int _mmc_suspend(struct mmc_host *host, enum mmc_poweroff_type pm_type)
>   			goto out;
>   	}
>   
> +	if (pm_type == MMC_NO_POWEROFF_SUSPEND) {
> +		if (host->retune_period) {
> +			mmc_retune_timer_stop(host);
> +			mmc_retune_needed(host);
> +		}
> +		mmc_card_set_suspended(host->card);
> +		goto out;
> +	}
> +
>   	if (mmc_card_can_poweroff_notify(host->card) &&
>   	    mmc_host_can_poweroff_notify(host, pm_type))
>   		err = mmc_poweroff_notify(host->card, notify_type);
> @@ -2193,9 +2203,15 @@ static void mmc_remove(struct mmc_host *host)
>    */
>   static int mmc_suspend(struct mmc_host *host)
>   {
> +	enum mmc_poweroff_type pm_type = MMC_POWEROFF_SUSPEND;
>   	int err;
>   
> -	err = _mmc_suspend(host, MMC_POWEROFF_SUSPEND);
> +	if (mmc_card_keep_power(host)) {
> +		pm_runtime_resume(&host->card->dev);
> +		pm_type = MMC_NO_POWEROFF_SUSPEND;
> +	}
> +
> +	err = _mmc_suspend(host, pm_type);
>   	if (!err) {
>   		pm_runtime_disable(&host->card->dev);
>   		pm_runtime_set_suspended(&host->card->dev);
> @@ -2260,7 +2276,13 @@ static int mmc_shutdown(struct mmc_host *host)
>    */
>   static int mmc_resume(struct mmc_host *host)
>   {
> +	if (mmc_card_keep_power(host)) {
> +		pm_runtime_set_active(&host->card->dev);
> +		mmc_card_clr_suspended(host->card);
> +	}
> +
>   	pm_runtime_enable(&host->card->dev);
> +	host->pm_flags &= ~MMC_PM_KEEP_POWER;
>   	return 0;
>   }
>