Re: [PATCH] ARM: dts: bcm2711-rpi-4-b: Use aliases to set custom MMC device index

From: Ariel D'Alessandro
Date: Mon Jun 13 2022 - 11:21:23 EST


Hi Peter,

On 6/12/22 17:38, Peter Robinson wrote:
> On Wed, Jun 8, 2022 at 1:35 PM Ariel D'Alessandro
> <ariel.dalessandro@xxxxxxxxxxxxx> wrote:
>>
>> Add MMC aliases to ensure that the /dev/mmcblk ID for SD card won't
>> change depending on the probe order of the MMC drivers.
>
> Is the bcm2711-rpi.dtsi a better place for it given there's other
> aliases there and it will be consistent across variations?

Yes, indeed, it makes sense moving it to bcm2711-rpi.dtsi

The other board what will be affected by this alias is the Raspberry Pi
Compute Module 4 IO Board, on which emmc2 is the eMMC. However, the
alias makes sense, to have that as the first mmc device.

Maybe we can add the alias as follows?

mmc0 = &emmc2; /* mmcblk0 for eMMC/SD */

Regards,
Ariel

>
>> Signed-off-by: Ariel D'Alessandro <ariel.dalessandro@xxxxxxxxxxxxx>
>> ---
>> arch/arm/boot/dts/bcm2711-rpi-4-b.dts | 4 ++++
>> 1 file changed, 4 insertions(+)
>>
>> diff --git a/arch/arm/boot/dts/bcm2711-rpi-4-b.dts b/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
>> index 4432412044de..780812542bad 100644
>> --- a/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
>> +++ b/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
>> @@ -14,6 +14,10 @@ chosen {
>> stdout-path = "serial1:115200n8";
>> };
>>
>> + aliases {
>> + mmc0 = &emmc2; /* mmcblk0 for SD */
>> + };
>> +
>> leds {
>> led-act {
>> gpios = <&gpio 42 GPIO_ACTIVE_HIGH>;
>> --
>> 2.34.1
>>
>>
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