Re: [PATCH 1/5] ARM: dts: at91: sama5d2_ptc_ek: fix sdmmc0 node description

From: Eugen.Hristev
Date: Thu Apr 02 2020 - 06:27:59 EST


On 02.04.2020 13:07, Ludovic Desroches - M43218 wrote:
> On 4/2/2020 11:20 AM, Eugen Hristev - M18282 wrote:
>> On 02.04.2020 01:15, Ludovic Desroches wrote:
>>> Remove non-removable and mmc-ddr-1_8v properties from the sdmmc0
>>> node which come probably from an unchecked copy/paste.
>>>
>>> Signed-off-by: Ludovic Desroches <ludovic.desroches@xxxxxxxxxxxxx>
>>> Fixes:42ed535595ec "ARM: dts: at91: introduce the sama5d2 ptc ek board"
>>> Cc: stable@xxxxxxxxxxxxxxx # 4.19 and later
>>> ---
>>> arch/arm/boot/dts/at91-sama5d2_ptc_ek.dts | 2 --
>>> 1 file changed, 2 deletions(-)
>>>
>>> diff --git a/arch/arm/boot/dts/at91-sama5d2_ptc_ek.dts b/arch/arm/boot/dts/at91-sama5d2_ptc_ek.dts
>>> index 1c24ac8019ba7..772809c54c1f3 100644
>>> --- a/arch/arm/boot/dts/at91-sama5d2_ptc_ek.dts
>>> +++ b/arch/arm/boot/dts/at91-sama5d2_ptc_ek.dts
>>> @@ -125,8 +125,6 @@ sdmmc0: sdio-host@a0000000 {
>>> bus-width = <8>;
>>> pinctrl-names = "default";
>>> pinctrl-0 = <&pinctrl_sdmmc0_default>;
>>> - non-removable;
>>> - mmc-ddr-1_8v;
>>
>> Hi Ludovic,
>>
>> I am not sure about the removal of mmc-ddr-1_8v; this means eMMCs
>> connected on this slot won't work in high speed mode, some people use
>> eMMC to SD-Card adapters and stick them into SD-Card slots.
>> Would it be a problem to keep this property here ?
>
> Hi Eugen,
>
> It's not a problem to keep it, but I don't think it makes sense. In this
> case mmc-ddr-3_3v should be added too.
>
> Will it work 'out of the box' with any eMMC to SD-Card adapters and
> eMMCs? I remember discussions where we said HW changes were needed to be
> able to select the voltage for the IOs other than using the VDDSEL
> signal of the controller.

Yes indeed , ddr-3_3v would be needed for those. I can follow up later
with a patch to add that if required.

Thanks !

>
> Regards
>
> Ludovic
>
>
>>
>> Thanks,
>> Eugen
>>
>>> status = "okay";
>>> };
>>>
>>>
>>
>