On Thu, Sep 10, 2020 at 4:16 PM Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx> wrote: > > Hi Hsin-Yi, > > On 10/9/20 9:57, Hsin-Yi Wang wrote: > > On Thu, Sep 10, 2020 at 3:20 PM Enric Balletbo i Serra > > <enric.balletbo@xxxxxxxxxxxxx> wrote: > >> > >> Hi Hsin-Yi, > >> > >> On 10/9/20 7:46, Hsin-Yi Wang wrote: > >>> Set uart0 iotype to mmio32 to make earlycon work with stdout-path. > >>> > >>> Signed-off-by: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx> > >>> --- > >>> arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi | 2 ++ > >>> 1 file changed, 2 insertions(+) > >>> > >>> diff --git a/arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi b/arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi > >>> index a5a12b2599a4a..d54e62f72c65d 100644 > >>> --- a/arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi > >>> +++ b/arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi > >>> @@ -1160,6 +1160,8 @@ &thermal { > >>> }; > >>> > >>> &uart0 { > >>> + reg-io-width = <4>; > >>> + reg-shift = <2>; > >> > >> I am wondering if these properties are common enough to go to mt8173.dtsi > >> instead of here. > >> > > Since stdout-path is set on elm.dtsi (using uart0), so I add this > > attribute here. > > > > Why needs to be defined in the same place that stdout-path is set? > > My guess is that reg-io-width and reg-shift are SoC specific, as they define how > the IO access to the register is done. In fact, I think that these properties > should be added in all the uarts, not only the one that has defined the stdout-path. > Okay, I'll apply them to all uart. Thanks.