[PATCH v7 2/3] dt-bindings: mmc: Add reset-card-at-resume property
Kamal Dasu <[email protected]>
| Newsgroups | gmane.linux.kernel,gmane.linux.kernel.mmc,gmane.linux.drivers.devicetree |
|---|---|
| Message-ID | <[email protected]> |
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(+) diff --git a/Documentation/devicetree/bindings/mmc/mmc-controller-common.yaml b/Documentation/devicetree/bindings/mmc/mmc-controller-common.yaml index c18bf0d6a56e..6929969ed5a2 100644 --- a/Documentation/devicetree/bindings/mmc/mmc-controller-common.yaml +++ b/Documentation/devicetree/bindings/mmc/mmc-controller-common.yaml @@ -293,6 +293,13 @@ properties: description: Preserves card power during a suspend/resume cycle. + reset-card-at-resume: + $ref: /schemas/types.yaml#/definitions/flag + description: + The HW/FW may have accessed the card during suspend/resume, + leaving it in an unknown state. Hence, before the card can be + used, it must be reset. + wakeup-source: $ref: /schemas/types.yaml#/definitions/flag description: -- 2.34.1