Re: [PATCH v3 1/2] dt-bindings: mmc: Document no-mmc-poweroff-suspend property

On Wed, Jul 22, 2026 at 05:14:16PM -0400, Kamal Dasu wrote:
> On some platforms, firmware accesses the (e)MMC card directly during
> system resume from Suspend-to-DRAM, before the kernel's own resume
> path has run, in order to load boot code using hard wired logic that
> is not field updatable. This requires the card to remain powered
> and responsive throughout suspend: it cannot be put to sleep, sent a
> power-off notification, or have its supply removed.
> 
> Add a no-mmc-poweroff-suspend flag property so affected boards can
> tell the mmc core to keep the card powered across suspend instead of
> sleeping or powering it off.
> 
> Signed-off-by: Kamal Dasu <[email protected]>
> ---
> Changes in v3:
>   - Renamed from no-mmc-sleep; dropped S_A_TIMEOUT framing per Ulf.
> 
> Changes in v2:
>   - New patch, replacing v1's card-level quirk, per Ulf.
> 
>  .../devicetree/bindings/mmc/mmc-controller-common.yaml | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/mmc/mmc-controller-common.yaml b/Documentation/devicetree/bindings/mmc/mmc-controller-common.yaml
> index 3d7195e9461c..5f7b3f8ef1dd 100644
> --- a/Documentation/devicetree/bindings/mmc/mmc-controller-common.yaml
> +++ b/Documentation/devicetree/bindings/mmc/mmc-controller-common.yaml
> @@ -232,6 +232,16 @@ properties:
>      description:
>        All eMMC HS400 modes are not supported.
>  
> +  no-mmc-poweroff-suspend:
> +    $ref: /schemas/types.yaml#/definitions/flag
> +    description:
> +      On this platform, firmware accesses the attached (e)MMC card
> +      directly during system resume, before the kernel's own resume
> +      path runs. The card must therefore stay powered throughout
> +      suspend, and the controller must not send it a sleep or
> +      power-off notification. The kernel re-initializes the card
> +      after resume, since firmware may have already reset it.

Isn't this exactly the same as keep-power-in-suspend?

Best regards,
Krzysztof