| Message ID | 20250320140040.162416-3-ulf.hansson@linaro.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mmc: core: Add support for graceful host removal for eMMC/SD | expand |
> 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@linaro.org> > --- > 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 >
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)) err = _mmc_resume(host); if (!err)
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@linaro.org> --- drivers/mmc/core/mmc.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-)