On Tue, 5 Sept 2023 at 14:00, Maxime Ripard <mripard@xxxxxxxxxx> wrote: > > On Tue, Sep 05, 2023 at 03:39:33PM +0530, Vignesh Raman wrote: > > Hi Dmitry, Maxime, > > > > On 05/09/23 14:13, Maxime Ripard wrote: > > > Hi, > > > > > > On Mon, Sep 04, 2023 at 07:59:26PM +0300, Dmitry Baryshkov wrote: > > > > On Mon, 4 Sept 2023 at 19:16, Vignesh Raman <vignesh.raman@xxxxxxxxxxxxx> wrote: > > > > > > > > > > Force db410c to host mode to fix network issue which results in failure > > > > > to mount root fs via NFS. > > > > > See https://gitlab.freedesktop.org/gfx-ci/linux/-/commit/cb72a629b8c15c80a54dda510743cefd1c4b65b8 > > > > > > > > > > Use fdtoverlay command to merge base device tree with an overlay > > > > > which contains the fix for USB controllers to work in host mode. > > > > > > > > > > Signed-off-by: Vignesh Raman <vignesh.raman@xxxxxxxxxxxxx> > > > > > --- > > > > > > > > > > v2: > > > > > - Use fdtoverlay command to merge overlay dtbo with the base dtb instead of modifying the kernel sources > > > > > > > > > > --- > > > > > drivers/gpu/drm/ci/build.sh | 5 +++++ > > > > > .../gpu/drm/ci/dt-overlays/apq8016-sbc-overlay.dts | 13 +++++++++++++ > > > > > 2 files changed, 18 insertions(+) > > > > > create mode 100644 drivers/gpu/drm/ci/dt-overlays/apq8016-sbc-overlay.dts > > > > > > > > > > diff --git a/drivers/gpu/drm/ci/build.sh b/drivers/gpu/drm/ci/build.sh > > > > > index 7b014287a041..92ffd98cd09e 100644 > > > > > --- a/drivers/gpu/drm/ci/build.sh > > > > > +++ b/drivers/gpu/drm/ci/build.sh > > > > > @@ -92,6 +92,11 @@ done > > > > > > > > > > if [[ -n ${DEVICE_TREES} ]]; then > > > > > make dtbs > > > > > + if [[ -e arch/arm64/boot/dts/qcom/apq8016-sbc.dtb ]]; then > > > > > + dtc -@ -I dts -O dtb -o drivers/gpu/drm/ci/dt-overlays/apq8016-sbc-overlay.dtbo drivers/gpu/drm/ci/dt-overlays/apq8016-sbc-overlay.dts > > > > > + fdtoverlay -i arch/arm64/boot/dts/qcom/apq8016-sbc.dtb -o arch/arm64/boot/dts/qcom/apq8016-sbc-overlay.dtb drivers/gpu/drm/ci/dt-overlays/apq8016-sbc-overlay.dtbo > > > > > + mv arch/arm64/boot/dts/qcom/apq8016-sbc-overlay.dtb arch/arm64/boot/dts/qcom/apq8016-sbc.dtb > > > > > + fi > > > > > cp ${DEVICE_TREES} /lava-files/. > > > > > fi > > > > > > > > > > diff --git a/drivers/gpu/drm/ci/dt-overlays/apq8016-sbc-overlay.dts b/drivers/gpu/drm/ci/dt-overlays/apq8016-sbc-overlay.dts > > > > > new file mode 100644 > > > > > index 000000000000..57b7604f1c23 > > > > > --- /dev/null > > > > > +++ b/drivers/gpu/drm/ci/dt-overlays/apq8016-sbc-overlay.dts > > > > > @@ -0,0 +1,13 @@ > > > > > +/dts-v1/; > > > > > +/plugin/; > > > > > + > > > > > +/ { > > > > > + fragment@0 { > > > > > + target-path = "/soc@0"; > > > > > + __overlay__ { > > > > > + usb@78d9000 { > > > > > + dr_mode = "host"; > > > > > + }; > > > > > + }; > > > > > + }; > > > > > +}; > > > > > -- > > > > > 2.40.1 > > > > > > > > Can we use normal dtso syntax here instead of defining fragments manually? > > > > > > What Dmitry is hinting about is to use the "Sugar Syntax". There a good documentation here: > > > https://source.android.com/docs/core/architecture/dto/syntax > > > > > > With the below DTO syntax, > > /dts-v1/; > > /plugin/; > > > > &usb { > > usb@78d9000 { > > dr_mode = "host"; > > }; > > }; > > > > Decoded dtbo file is, > > /dts-v1/; > > > > / { > > > > fragment@0 { > > target = <0xffffffff>; > > > > __overlay__ { > > > > usb@78d9000 { > > dr_mode = "host"; > > }; > > }; > > }; > > > > __fixups__ { > > usb = "/fragment@0:target:0"; > > }; > > }; > > > > With the previous fix using fragment we get, > > / { > > > > fragment@0 { > > target-path = "/soc@0"; > > > > __overlay__ { > > > > usb@78d9000 { > > dr_mode = "host"; > > }; > > }; > > }; > > }; > > > > Decoded apq8016-sbc.dtb file with the fix (setting dr_mode to host) is, > > /dts-v1/; > > / { > > soc@0 { > > usb@78d9000 { > > dr_mode = "host"; > > }; > > }; > > }; > > > > How can set the target to "soc@0" using the DTO syntax? > > To strictly answer your question, that would be something like > > &{/soc@0} { > usb@78d9000 { > dr_mode = "host"; > }; > }; > > You can simplify this further however by doing: > > > &{/soc@0/usb@78d9000} { > dr_mode = "host"; > }; > > Also, that node actually has a label ("usb"), defined here: > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm64/boot/dts/qcom/msm8916.dtsi#n2322 > > So you can end up with > > &usb { > dr_mode = "host"; > }; ... which is the simplest and thus more robust one. > All of them should be equivalent to the one you had in your patch. > > Maxime -- With best wishes Dmitry
