Re: [PATCH 1/3] dt-bindings: mmc: meson-gx: add ddr-access-quirk property

From: Neil Armstrong
Date: Wed May 15 2019 - 08:45:50 EST


On 15/05/2019 13:37, Ulf Hansson wrote:
> On Mon, 13 May 2019 at 11:16, Neil Armstrong <narmstrong@xxxxxxxxxxxx> wrote:
>>
>> On the Amlogic G12A SoC family, (only) the SDIO controller has a bug which
>> makes any DDR access from the MMC controller fail.
>>
>> Add the amlogic,ddr-access-quirk property so signal this particular
>> controller has this bug and needs a quirk to work properly.
>>
>> Signed-off-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
>> ---
>> Documentation/devicetree/bindings/mmc/amlogic,meson-gx.txt | 4 ++++
>> 1 file changed, 4 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/mmc/amlogic,meson-gx.txt b/Documentation/devicetree/bindings/mmc/amlogic,meson-gx.txt
>> index 13e70409e8ac..f8914dab06c6 100644
>> --- a/Documentation/devicetree/bindings/mmc/amlogic,meson-gx.txt
>> +++ b/Documentation/devicetree/bindings/mmc/amlogic,meson-gx.txt
>> @@ -22,6 +22,10 @@ Required properties:
>> clock rate requested by the MMC core.
>> - resets : phandle of the internal reset line
>>
>> +Optional properties:
>> +- amlogic,ddr-access-quirk: set when HW cannot access the DDR memory, like on
>> + the G12A SDIO controller.
>
> As stated on the other patch, may I suggest to use DRAM instead of DDR.

Indeed, may be more accurate.

>
> Moreover, please mention that this is about the internal DMA support
> of the controller.

Ok

>
>> +
>> Example:
>>
>> sd_emmc_a: mmc@70000 {
>> --
>> 2.21.0
>>
>
> Kind regards
> Uffe
>