> To manage a graceful power-off of the eMMC card during platform shutdown,
> the preferred option is to use the poweroff-notification command.
>
> Due to an earlier suspend request the eMMC may already have been properly
> powered-off, hence we are sometimes leaving the eMMC in its current state.
> However, in one case when the host has
> MMC_CAP2_FULL_PWR_CYCLE_IN_SUSPEND
> set we may unnecessarily restore the power to the eMMC, let's avoid this.
>
> Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
> ---
> drivers/mmc/core/mmc.c | 17 ++++++++++++++---
> 1 file changed, 14 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index
> 3424bc9e20c5..400dd0449fec 100644
> --- a/drivers/mmc/core/mmc.c
> +++ b/drivers/mmc/core/mmc.c
> @@ -2014,6 +2014,18 @@ static bool mmc_can_poweroff_notify(const
> struct mmc_card *card)
> (card->ext_csd.power_off_notification ==
> EXT_CSD_POWER_ON); }
>
> +static bool mmc_may_poweroff_notify(const struct mmc_host *host,
> + bool is_suspend)
> +{
> + if (host->caps2 & MMC_CAP2_FULL_PWR_CYCLE)
> + return true;
> +
> + if (host->caps2 & MMC_CAP2_FULL_PWR_CYCLE_IN_SUSPEND &&
> is_suspend)
> + return true;
> +
> + return !is_suspend;
> +}
> +
> static int mmc_poweroff_notify(struct mmc_card *card, unsigned int
> notify_type) {
> unsigned int timeout = card->ext_csd.generic_cmd6_time; @@ -
> 2124,8 +2136,7 @@ static int _mmc_suspend(struct mmc_host *host, bool
> is_suspend)
> goto out;
>
> if (mmc_can_poweroff_notify(host->card) &&
> - ((host->caps2 & MMC_CAP2_FULL_PWR_CYCLE) || !is_suspend ||
> - (host->caps2 & MMC_CAP2_FULL_PWR_CYCLE_IN_SUSPEND)))
> + mmc_may_poweroff_notify(host, is_suspend))
> err = mmc_poweroff_notify(host->card, notify_type);
> else if (mmc_can_sleep(host->card))
> err = mmc_sleep(host);
> @@ -2191,7 +2202,7 @@ static int mmc_shutdown(struct mmc_host *host)
> * before we can shutdown it properly.
> */
> if (mmc_can_poweroff_notify(host->card) &&
> - !(host->caps2 & MMC_CAP2_FULL_PWR_CYCLE))
> + !mmc_may_poweroff_notify(host, true))
I guess this deserve some extra documentation because:
If MMC_CAP2_FULL_PWR_CYCLE is not set but MMC_CAP2_FULL_PWR_CYCLE_IN_SUSPEND is set,
!mmc_may_poweroff_notify(host, true) will evaluate to false while !(host->caps2 & MMC_CAP2_FULL_PWR_CYCLE) will evaluate to true.
Thanks,
Avri
> err = _mmc_resume(host);
>
> if (!err)
> --
> 2.43.0
>
