Re: [PATCH 1/2] dt-bindings: mmc: Add post-power-off-delay-ms property

On Fri, Jul 17, 2026 at 7:40 PM Judith Mendez <[email protected]> wrote:
>
> Hi Ulf,
>
> On 7/17/26 5:21 AM, Ulf Hansson wrote:
> > On Fri, Jul 17, 2026 at 1:26 AM Judith Mendez <[email protected]> wrote:
> >>
> >> Add post-power-off-delay-ms property to MMC controller common.
> >>
> >> This property shall be used to specify delay if needed after
> >> deasserting power during MMC power cycles.
> >
> > Please clarify with some additional information from the cover-letter,
> > like "specify custom delays after MMC power off to work around
> > hardware issues such as slow RC circuites on MMC VDD rails."
> >
> >>
> >> Signed-off-by: Judith Mendez <[email protected]>
> >> ---
> >>   .../devicetree/bindings/mmc/mmc-controller-common.yaml    | 8 ++++++++
> >>   1 file changed, 8 insertions(+)
> >>
> >> diff --git a/Documentation/devicetree/bindings/mmc/mmc-controller-common.yaml b/Documentation/devicetree/bindings/mmc/mmc-controller-common.yaml
> >> index 3d7195e9461c3..3ff68d32a308f 100644
> >> --- a/Documentation/devicetree/bindings/mmc/mmc-controller-common.yaml
> >> +++ b/Documentation/devicetree/bindings/mmc/mmc-controller-common.yaml
> >> @@ -275,6 +275,14 @@ properties:
> >>         not available.
> >>       default: 10
> >>
> >> +  post-power-off-delay-ms:
> >
> > For mmc-pwrseq-simple we already have "power-off-delay-us", perhaps
> > better to re-use that name instead.
>
> Besides having the same dt property name as mmc-pwrseq-simple what is
> the benefit of switching to power-off-delay-us?

Using ms as the unit is limiting and completely unnecessary. What is
some HW is fine with 300 us, for example.

>
> All values will have to be in us instead of ms and thus will look a bit
> less clean in code. If it is just a naming  preference, I do prefer
> the current name in this version, please let me know if we can keep:
> post-power-off-delay-ms.

The code is a separate thing, this is the DT property for supporting
different HWs.

[...]

Kind regards
Uffe