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SubjectRe: [PATCH v3] mmc: host: sdhci-sprd: Fix the incorrect soft reset operation when runtime resuming
On Tue, 16 Jul 2019 at 18:40, Adrian Hunter <adrian.hunter@intel.com> wrote:
>
> On 16/07/19 11:39 AM, Baolin Wang wrote:
> > In sdhci_runtime_resume_host() function, we will always do software reset
> > for all, which will cause Spreadtrum host controller work abnormally after
> > resuming.
> >
> > Thus for Spreadtrum platform that do not power down the SD/eMMC card during
> > runtime suspend, we should not do software reset for all. To fix this
> > issue, adding a specific reset operation that add one condition to validate
> > the MMC_CAP_AGGRESSIVE_PM to decide if we can do software reset for all or
> > just reset command and data lines.
> >
> > Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
> > ---
> > Changes from v2:
> > - Simplify the sdhci_sprd_reset() by issuing sdhci_reset().
> >
> > Changes from v1:
> > - Add a specific reset operation instead of changing the core to avoid
> > affecting other hardware.
> > ---
> > drivers/mmc/host/sdhci-sprd.c | 19 ++++++++++++++++++-
> > 1 file changed, 18 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/mmc/host/sdhci-sprd.c b/drivers/mmc/host/sdhci-sprd.c
> > index 603a5d9..bc9393c 100644
> > --- a/drivers/mmc/host/sdhci-sprd.c
> > +++ b/drivers/mmc/host/sdhci-sprd.c
> > @@ -373,6 +373,23 @@ static unsigned int sdhci_sprd_get_max_timeout_count(struct sdhci_host *host)
> > return 1 << 31;
> > }
> >
> > +static void sdhci_sprd_reset(struct sdhci_host *host, u8 mask)
> > +{
> > + struct mmc_host *mmc = host->mmc;
> > +
> > + /*
> > + * When try to reset controller after runtime suspend, we should not
> > + * reset for all if the SD/eMMC card is not power down, just reset
> > + * command and data lines instead. Otherwise will meet some strange
> > + * behaviors for Spreadtrum host controller.
> > + */
> > + if (host->runtime_suspended && (mask & SDHCI_RESET_ALL) &&
> > + !(mmc->caps & MMC_CAP_AGGRESSIVE_PM))
>
> MMC_CAP_AGGRESSIVE_PM does not necessarily mean that the card will have been
> runtime suspended.
>
> What about checking if the card power is on? i.e.

Yes, you are totally correct. I'll fix this in next version. Thanks
for your comments.

> if (host->runtime_suspended && (mask & SDHCI_RESET_ALL) &&
> mmc->ios.power_mode == MMC_POWER_ON)
>
> > + mask = SDHCI_RESET_CMD | SDHCI_RESET_DATA;
> > +
> > + sdhci_reset(host, mask);
> > +}
> > +
> > static struct sdhci_ops sdhci_sprd_ops = {
> > .read_l = sdhci_sprd_readl,
> > .write_l = sdhci_sprd_writel,
> > @@ -381,7 +398,7 @@ static unsigned int sdhci_sprd_get_max_timeout_count(struct sdhci_host *host)
> > .get_max_clock = sdhci_sprd_get_max_clock,
> > .get_min_clock = sdhci_sprd_get_min_clock,
> > .set_bus_width = sdhci_set_bus_width,
> > - .reset = sdhci_reset,
> > + .reset = sdhci_sprd_reset,
> > .set_uhs_signaling = sdhci_sprd_set_uhs_signaling,
> > .hw_reset = sdhci_sprd_hw_reset,
> > .get_max_timeout_count = sdhci_sprd_get_max_timeout_count,
> >
>


--
Baolin Wang
Best Regards

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