Re: [PATCH v2 2/7] drm: ci: Force db410c to host mode
From: Vignesh Raman
Date: Tue Sep 05 2023 - 12:33:37 EST
Hi,
On 05/09/23 16:40, Dmitry Baryshkov wrote:
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";
};
The above works. Thanks.
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.
Should it be,
&{/soc@0/usb} {
dr_mode = "host";
};
I will send a v3 version for this. Thank you.
Regards,
Vignesh