Hi Neil, On Mon, May 13, 2019 at 11:16 AM 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> Reviewed-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx> > --- > 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. (I believe we cannot use a standard property like "dma-ranges" to disable DMA access) personally I prefer "amlogic,no-direct-memory-access" or "amlogic,no-ddr-access", but if Rob is happy with the current naming then I'm happy as well Regards Martin
