Re: [PATCH v7 2/3] dt-bindings: mmc: Add reset-card-at-resume property

Rob Herring <[email protected]> Fri, 7 Aug 2026 08:56:38 -0500
Newsgroups org.kernel.vger.linux-mmc,org.kernel.vger.linux-devicetree,org.kernel.vger.linux-kernel
Message-ID <[email protected]>
On Wed, Aug 05, 2026 at 06:24:59PM -0400, Kamal Dasu wrote:
> On some platforms, firmware or other hardware accesses the card
> during suspend/resume, before the kernel's own resume path has run,
> leaving the card in a state the kernel can no longer assume it knows.
> Add a flag property so such boards can tell the mmc core the card
> needs to be reset before it can be used again.
> 
> This is expected to be paired with keep-power-in-suspend on boards
> whose firmware needs the card to stay powered and live throughout
> suspend: since the card is never power-cycled, nothing else would
> force it back to a known state on resume.
> 
> Signed-off-by: Kamal Dasu <[email protected]>
> Reviewed-by: Krzysztof Kozlowski <[email protected]>
> ---
> Changes in v7:
>   - Added Krzysztof's Reviewed-by.
>   - No other change here; patch 3/3 now requires this property
>     alongside keep-power-in-suspend for (e)MMC rather than treating
>     them as fully independent in the driver -- see that patch's
>     changelog.
> 
> Changes in v6:
>   - New patch, per Ulf's suggestion: rather than fold "needs a reset
>     at resume" into keep-power-in-suspend's own meaning, describe it
>     as its own independent property, so the two can be combined only
>     where actually needed (brcmstb sets both; SDIO's existing
>     keep-power-in-suspend users are unaffected and set neither this
>     nor a reset).
> 
>  Documentation/devicetree/bindings/mmc/mmc-controller-common.yaml | 7 +++++++
>  1 file changed, 7 insertions(+)

sashiko issue needs to be addressed