| Message ID | 20250422220512.297396-2-jm@ti.com |
|---|---|
| State | New |
| Headers | show |
| Series | Add ti,suppress-v1p8-ena | expand |
On Tue, Apr 22, 2025 at 05:05:10PM GMT, Judith Mendez wrote: > Some Microcenter/Patriot SD cards and Kingston eMMC are failing init > across Sitara K3 boards. Init failure is due to the sequence when > V1P8_SIGNAL_ENA is set. The V1P8_SIGNAL_ENA has a timing component tied > to it where if set, switch to full-cycle timing happens. The failing > cards do not like change to full-cycle timing before changing bus > width, so add flag to sdhci-am654 binding to suppress V1P8_SIGNAL_ENA > before changing bus width. The switch to full-cycle timing should happen > with HIGH_SPEED_ENA after change of bus width. > > Signed-off-by: Judith Mendez <jm@ti.com> > --- > Documentation/devicetree/bindings/mmc/sdhci-am654.yaml | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/Documentation/devicetree/bindings/mmc/sdhci-am654.yaml b/Documentation/devicetree/bindings/mmc/sdhci-am654.yaml > index 676a74695389..0f92bbf8e13b 100644 > --- a/Documentation/devicetree/bindings/mmc/sdhci-am654.yaml > +++ b/Documentation/devicetree/bindings/mmc/sdhci-am654.yaml > @@ -201,6 +201,11 @@ properties: > and the controller is required to be forced into Test mode > to set the TESTCD bit. > > + ti,suppress-v1p8-ena: Do not tell what the drivers should do, but tell what is the issue with the hardware, e.g. some cards do not like full-cycle.... and this will also hint you that it should be most likely generic, not specific to this device. > + $ref: /schemas/types.yaml#/definitions/flag > + description: Best regards, Krzysztof
Hi Krzysztof, On 4/25/25 2:48 AM, Krzysztof Kozlowski wrote: > On Tue, Apr 22, 2025 at 05:05:10PM GMT, Judith Mendez wrote: >> Some Microcenter/Patriot SD cards and Kingston eMMC are failing init >> across Sitara K3 boards. Init failure is due to the sequence when >> V1P8_SIGNAL_ENA is set. The V1P8_SIGNAL_ENA has a timing component tied >> to it where if set, switch to full-cycle timing happens. The failing >> cards do not like change to full-cycle timing before changing bus >> width, so add flag to sdhci-am654 binding to suppress V1P8_SIGNAL_ENA >> before changing bus width. The switch to full-cycle timing should happen >> with HIGH_SPEED_ENA after change of bus width. >> >> Signed-off-by: Judith Mendez <jm@ti.com> >> --- >> Documentation/devicetree/bindings/mmc/sdhci-am654.yaml | 5 +++++ >> 1 file changed, 5 insertions(+) >> >> diff --git a/Documentation/devicetree/bindings/mmc/sdhci-am654.yaml b/Documentation/devicetree/bindings/mmc/sdhci-am654.yaml >> index 676a74695389..0f92bbf8e13b 100644 >> --- a/Documentation/devicetree/bindings/mmc/sdhci-am654.yaml >> +++ b/Documentation/devicetree/bindings/mmc/sdhci-am654.yaml >> @@ -201,6 +201,11 @@ properties: >> and the controller is required to be forced into Test mode >> to set the TESTCD bit. >> >> + ti,suppress-v1p8-ena: > > Do not tell what the drivers should do, but tell what is the issue with > the hardware, e.g. some cards do not like full-cycle.... and this will > also hint you that it should be most likely generic, not specific to > this device. > Thanks for your review, but this patch has been dropped in v4 since we adopted a new implementation [0] using compatible string. [0] https://lore.kernel.org/linux-devicetree/20250423180809.l3l6sfbwquaaazar@shrank/ ~ Judith
diff --git a/Documentation/devicetree/bindings/mmc/sdhci-am654.yaml b/Documentation/devicetree/bindings/mmc/sdhci-am654.yaml index 676a74695389..0f92bbf8e13b 100644 --- a/Documentation/devicetree/bindings/mmc/sdhci-am654.yaml +++ b/Documentation/devicetree/bindings/mmc/sdhci-am654.yaml @@ -201,6 +201,11 @@ properties: and the controller is required to be forced into Test mode to set the TESTCD bit. + ti,suppress-v1p8-ena: + $ref: /schemas/types.yaml#/definitions/flag + description: + When present, V1P8_SIGNAL_ENA shall be suppressed. + required: - compatible - reg
Some Microcenter/Patriot SD cards and Kingston eMMC are failing init across Sitara K3 boards. Init failure is due to the sequence when V1P8_SIGNAL_ENA is set. The V1P8_SIGNAL_ENA has a timing component tied to it where if set, switch to full-cycle timing happens. The failing cards do not like change to full-cycle timing before changing bus width, so add flag to sdhci-am654 binding to suppress V1P8_SIGNAL_ENA before changing bus width. The switch to full-cycle timing should happen with HIGH_SPEED_ENA after change of bus width. Signed-off-by: Judith Mendez <jm@ti.com> --- Documentation/devicetree/bindings/mmc/sdhci-am654.yaml | 5 +++++ 1 file changed, 5 insertions(+)