Re: [PATCH RESEND v3 1/3] dt-bindings: mmc: sdhci-am654: Add ti,suppress-v1p8-ena

Judith Mendez
2025-04-25T14:19:51Z

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