Re: [PATCH V4 4/4] arm64: dts: qcom: sm8550: Remove SDR104/SDR50 broken capabilities

[Sarthak Garg]

On 8/5/2025 3:29 PM, Dmitry Baryshkov wrote:
> On Tue, Aug 05, 2025 at 02:49:29PM +0530, Sarthak Garg wrote:
> > On 8/1/2025 2:32 PM, Krzysztof Kozlowski wrote:
> > > On 01/08/2025 10:45, Sarthak Garg wrote:
> > > > The kernel now handles level shifter limitations affecting SD card
> > > > modes, making it unnecessary to explicitly disable SDR104 and SDR50
> > > > capabilities in the device tree.
> > > >
> > > > However, due to board-specific hardware constraints particularly related
> > > > to level shifter in this case the maximum frequency for SD High-Speed
> > > > (HS) mode must be limited to 37.5 MHz to ensure reliable operation of SD
> > > > card in HS mode. This is achieved using the max-sd-hs-frequency property
> > > > in the board DTS.
> > > >
> > > > Signed-off-by: Sarthak Garg <quic_sartgarg@xxxxxxxxxxx>
> > > > ---
> > > >    arch/arm64/boot/dts/qcom/sm8550-hdk.dts                     | 1 +
> > > >    arch/arm64/boot/dts/qcom/sm8550-mtp.dts                     | 1 +
> > > >    arch/arm64/boot/dts/qcom/sm8550-sony-xperia-yodo-pdx234.dts | 1 +
> > > >    arch/arm64/boot/dts/qcom/sm8550.dtsi                        | 3 ---
>
> You missed several devices which use SM8550. Please fix that.
>
> > > >    4 files changed, 3 insertions(+), 3 deletions(-)
> > >
> > > This will break MMC for all of the users and nothing in commit msg or
> > > cover letter explains that or mentions merging strategy.
> > >
> > > Exactly this case is covered by your internal guideline, no? Please read it.
> > >
> > > Best regards,
> > > Krzysztof
> >
> > Just to make sure I’m addressing the right concern — are you primarily
> > worried about the introduction of the max-sd-hs-frequency property in the
> > board DTS files, or about the removal of the sdhci-caps-mask
> > from the common sm8550.dtsi?
>
> This patch requires all previous patches to work, so it can not be
> applied in parallel. It should be applied after the previous patches are
> merged by MMC maintainers and then available in the Bjorn's tree. This
> requires either skipping a release for this patch or using an immutable
> tag for the MMC patches. All these deteails should be explained in the
> cover letter.

As mentioned in reply to Krzysztof's previous comment we are planning to 
drop the plan to modify broken capabilities for SM8550 in the current 
cycle. The removal of SDR104/SDR50 caps will be revisited for upcoming 
targets, where we can ensure proper validation and alignment with MMC 
patch dependencies.

Best regards,
Sarthak