diff mbox series

[v2] mmc: host: Wait for Vdd to settle on card power off

Message ID 20250314195021.1588090-1-erick.shepherd@ni.com (mailing list archive)
State New
Headers show
Series [v2] mmc: host: Wait for Vdd to settle on card power off | expand

Commit Message

Erick Shepherd March 14, 2025, 7:50 p.m. UTC
The SD spec version 6.0 section 6.4.1.5 requires that Vdd must be
lowered to less than 0.5V for a minimum of 1 ms when powering off a
card. Increase wait to 15 ms so that voltage has time to drain down
to 0.5V and cards can power off correctly. Issues with voltage drain
time were only observed on Apollo Lake and Bay Trail host controllers
so this fix is limited to those devices.

Signed-off-by: Erick Shepherd <erick.shepherd@ni.com>
---
 drivers/mmc/host/sdhci-pci-core.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

Comments

Adrian Hunter March 20, 2025, 7:25 a.m. UTC | #1
On 14/03/25 21:50, Erick Shepherd wrote:
> The SD spec version 6.0 section 6.4.1.5 requires that Vdd must be
> lowered to less than 0.5V for a minimum of 1 ms when powering off a
> card. Increase wait to 15 ms so that voltage has time to drain down
> to 0.5V and cards can power off correctly. Issues with voltage drain
> time were only observed on Apollo Lake and Bay Trail host controllers
> so this fix is limited to those devices.
> 
> Signed-off-by: Erick Shepherd <erick.shepherd@ni.com>

Can we leave a blank line after the block.  It was that way before.

With that, you can add:

Acked-by: Adrian Hunter <adrian.hunter@intel.com>

> ---
>  drivers/mmc/host/sdhci-pci-core.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c
> index 1f0bd723f011..b1f7c11ea61e 100644
> --- a/drivers/mmc/host/sdhci-pci-core.c
> +++ b/drivers/mmc/host/sdhci-pci-core.c
> @@ -610,9 +610,12 @@ static void sdhci_intel_set_power(struct sdhci_host *host, unsigned char mode,
>  
>  	sdhci_set_power(host, mode, vdd);
>  
> -	if (mode == MMC_POWER_OFF)
> +	if (mode == MMC_POWER_OFF) {
> +		if (slot->chip->pdev->device == PCI_DEVICE_ID_INTEL_APL_SD ||
> +		    slot->chip->pdev->device == PCI_DEVICE_ID_INTEL_BYT_SD)
> +			usleep_range(15000, 17500);
>  		return;
> -
> +	}

Blank line here

>  	/*
>  	 * Bus power might not enable after D3 -> D0 transition due to the
>  	 * present state not yet having propagated. Retry for up to 2ms.
Ulf Hansson March 20, 2025, 2:16 p.m. UTC | #2
On Thu, 20 Mar 2025 at 08:26, Adrian Hunter <adrian.hunter@intel.com> wrote:
>
> On 14/03/25 21:50, Erick Shepherd wrote:
> > The SD spec version 6.0 section 6.4.1.5 requires that Vdd must be
> > lowered to less than 0.5V for a minimum of 1 ms when powering off a
> > card. Increase wait to 15 ms so that voltage has time to drain down
> > to 0.5V and cards can power off correctly. Issues with voltage drain
> > time were only observed on Apollo Lake and Bay Trail host controllers
> > so this fix is limited to those devices.
> >
> > Signed-off-by: Erick Shepherd <erick.shepherd@ni.com>
>
> Can we leave a blank line after the block.  It was that way before.
>
> With that, you can add:
>
> Acked-by: Adrian Hunter <adrian.hunter@intel.com>

Applied for next with the suggested change, thanks!

Kind regards
Uffe


>
> > ---
> >  drivers/mmc/host/sdhci-pci-core.c | 7 +++++--
> >  1 file changed, 5 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c
> > index 1f0bd723f011..b1f7c11ea61e 100644
> > --- a/drivers/mmc/host/sdhci-pci-core.c
> > +++ b/drivers/mmc/host/sdhci-pci-core.c
> > @@ -610,9 +610,12 @@ static void sdhci_intel_set_power(struct sdhci_host *host, unsigned char mode,
> >
> >       sdhci_set_power(host, mode, vdd);
> >
> > -     if (mode == MMC_POWER_OFF)
> > +     if (mode == MMC_POWER_OFF) {
> > +             if (slot->chip->pdev->device == PCI_DEVICE_ID_INTEL_APL_SD ||
> > +                 slot->chip->pdev->device == PCI_DEVICE_ID_INTEL_BYT_SD)
> > +                     usleep_range(15000, 17500);
> >               return;
> > -
> > +     }
>
> Blank line here
>
> >       /*
> >        * Bus power might not enable after D3 -> D0 transition due to the
> >        * present state not yet having propagated. Retry for up to 2ms.
>
diff mbox series

Patch

diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c
index 1f0bd723f011..b1f7c11ea61e 100644
--- a/drivers/mmc/host/sdhci-pci-core.c
+++ b/drivers/mmc/host/sdhci-pci-core.c
@@ -610,9 +610,12 @@  static void sdhci_intel_set_power(struct sdhci_host *host, unsigned char mode,
 
 	sdhci_set_power(host, mode, vdd);
 
-	if (mode == MMC_POWER_OFF)
+	if (mode == MMC_POWER_OFF) {
+		if (slot->chip->pdev->device == PCI_DEVICE_ID_INTEL_APL_SD ||
+		    slot->chip->pdev->device == PCI_DEVICE_ID_INTEL_BYT_SD)
+			usleep_range(15000, 17500);
 		return;
-
+	}
 	/*
 	 * Bus power might not enable after D3 -> D0 transition due to the
 	 * present state not yet having propagated. Retry for up to 2ms.