Re: [PATCH 2/2] qcom_defconfig: Disable MMC HS200 mode support

[Sumit Garg <sumit.garg@kernel.org>]

On Mon, Apr 07, 2025 at 04:30:44PM +0200, Caleb Connolly wrote:
> 
> 
> On 4/7/25 15:28, Sumit Garg wrote:
> > From: Sumit Garg <sumit.garg@oss.qualcomm.com>
> > 
> > Currently the msm_sdhci doesn't yet support DLL configurations which are
> > required to enable bus speeds greater that 100MHz. So disable HS200 mode
> > support as of now as it requires bus speeds of 200MHz.
> > 
> > This should fix eMMC issues reported on RB1.
> 
> This fixes the write corruption issues? Nice find!!

Yeah, thanks.

> 
> Is this a problem on ALL Qualcomm platforms? the sdcard seems to work fine
> on other boards, would this reduce their performance?

Yes this problem should affect all Qualcomm platforms but it hasn't been
seen there as mostly SD cards available don't support HS200 mode. The SD
cards usually works in high speed mode whose performance remains
unaffected by this change. It only affects RB1/RB2 as eMMC flash on
these support HS200 mode but the U-Boot driver currently is incapable of
supporting that.

-Sumit

> 
> > 
> > Signed-off-by: Sumit Garg <sumit.garg@oss.qualcomm.com>
> > ---
> >   configs/qcom_defconfig | 1 -
> >   1 file changed, 1 deletion(-)
> > 
> > diff --git a/configs/qcom_defconfig b/configs/qcom_defconfig
> > index a2b54b95f19..537806450dc 100644
> > --- a/configs/qcom_defconfig
> > +++ b/configs/qcom_defconfig
> > @@ -81,7 +81,6 @@ CONFIG_QCOM_HYP_SMMU=y
> >   CONFIG_MISC=y
> >   CONFIG_NVMEM=y
> >   CONFIG_I2C_EEPROM=y
> > -CONFIG_MMC_HS200_SUPPORT=y
> >   CONFIG_MMC_SDHCI=y
> >   CONFIG_MMC_SDHCI_ADMA=y
> >   CONFIG_MMC_SDHCI_MSM=y
> 
> -- 
> Caleb (they/them)
>