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 >