Re: [PATCH 1/2] dt-bindings: mmc: Add post-power-off-delay-ms property
From: Judith Mendez
Date: Fri Jul 17 2026 - 16:11:00 EST
Hi Ulf,
On 7/17/26 5:21 AM, Ulf Hansson wrote:
On Fri, Jul 17, 2026 at 1:26 AM Judith Mendez <jm@xxxxxx> 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 <jm@xxxxxx>
---
.../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.
+ description:
+ The presence of this property indicates that the card requires a
+ delay (in milliseconds) after power off before the next power on.
Again, maybe something to indicate this is specific like "specify
custom delays after MMC power off to work around
hardware issues such as slow RC circuites on MMC VDD rails."
+ $ref: /schemas/types.yaml#/definitions/uint32
+ minimum: 0
+ maximum: 10000
Are the above limits needed at all?
I would like to keep the limits from minimum 1ms to 10000ms just because
likely someone will go ahead and add a huge delay and wonder why their
board just crashed. I think 10000ms or 10s is large enough, what do you
think?
...