JETSON-AGX-8GB，can't boot up after flashing changed devicetree

[g_shilong]

I designed a customer board for my jetson-xavier-8GB. HDMI channal is ch1 instead of ch2 (P2822 board used).So,I changed and replaced original devicetree as fllowing pictures,but module can’t boot up. Is there a problem with the modification ?

[WayneWWW]

Hi,

The way you are sharing device tree does not provide much detail… Please share the diff file for what you changed…

BTW, I don’t think what you changed here is correct. For example, hda is not related to what you changed.

Changing SOR0 is also not sufficient for what you want…

[g_shilong]

The “sor” is the subnode of node“host1x".

agx-8gb.dts (346.5 KB)

[WayneWWW]

Hi

我講得明白一點. 你改完的東西跟你想要做的事情一點關係都沒有

DP0/DP1/DP2這三根pin對應的就是 device tree裡面的SOR0(sor)/SOR1/SOR2.
如果你的硬體改動是希望把HDMI從預設的SOR2移動到SOR1. 那麼改SOR0這件事情就是錯的. 因為根本改錯node…

還有 hda是給audio用的 改那個對你的目的也沒有太大的幫助…

你應該要做的是看一下原本的nvdisplay 跟sor的mapping關係 然後參考sor2的寫法把 sor1的HDMI給打開來…

[g_shilong]

Thank you first. I followed your suggestion,module can boot up,but HDMI1 port doesn’t work .Uart debug shows “31c0000.i2c”,it seems like errors.

agx-8gb-7.dts (346.5 KB)
session7.log (36.0 KB)

[WayneWWW]

1. 你的 sor1這個還是在用DP

nvidia,active-panel = <0x7d>;

2. Devkit 上面type C for DP的設定用不上了 所以也得拿掉

[ 16.874901] Could not get extcon-dev /host1x/nvdisplay@15210000:typec0(0)
[ 16.876136] Could not get extcon-dev /host1x/nvdisplay@15220000:typec1(1)

hardware/nvidia/platform/t19x/galen/kernel-dts/common/tegra194-p2888-0001-p2822-0000-common.dtsi裡面的type C 0/1還有那個sor0/1的 nvidia,typec-port 也請拿掉

3. 你的log沒有用. 麻煩把quiet 從/boot/extlinux/extlinux.conf拿掉之後重新dump一次…

[g_shilong]

For step1:

step2:

I search at root directory ,but can’t found tegra194-p2888-0001-p2822-0000-common.dtsi . My system version is R32.4.3

So, I delect the node “15210000” and “15220000” in dts document,and de-compile it to dtb .

step3:
delect “quiet” from /boot/extlinux/extlinux.conf
session8.log (90.8 KB)

Finally, HDMI1 can’t still work.

[WayneWWW]

請問一下你是怎麼改device tree的？

我們有提供device tree的原始source code. 我所提到的那個檔案就在那邊
正常來說我們都是透過原檔在更改device tree的. 不然透過dtc轉檔的話很多都是hex value, 你也不好看懂.

Jetson Linux Archive

我也不是叫你刪除這兩個節點… 刪掉了你的display就不會動了 … 麻煩進入狀況一下…

So, I delect the node “15210000” and “15220000” in dts document,and de-compile it to dtb .

[g_shilong]

I copy the “tegra194-p2888-0006-p2822-0000.dtb” from /boot/dtb ,and compile it to dts, change nodes from this dts.Then de-compile it to dtb and place original location, change the extlinux.conf at the same time.

[WayneWWW]

如果你對device tree很熟, 你想要怎樣改都沒有關係, 確認內容是正確就可以了

如果你對device tree不熟, 麻煩照著我們文件做吧. 不然雞同鴨講. 改一堆hex value你也不知道為何要改
https://docs.nvidia.com/jetson/archives/l4t-archived/l4t-3261/index.html#page/Tegra%20Linux%20Driver%20Package%20Development%20Guide/kernel_custom.html#

另外, 我這裡說的事情跟hdmi無關 只是build device tree的方法而已

[g_shilong]

OK,I will download the source code ,and change as your suggestions.

[WayneWWW]

大概講解一下 dispaly device tree的架構

SORx代表的是你的hardware pin 對應: SOR0 → DP0. SOR1-> DP1. SOR2->DP2.
所以你的板子, sor1務必enabled. 而且要設成hdmi mode.

每一個SOR都要有一個nvdisplay去認領. Nvdisplay才是software controller. 每一個nvdisplay要控制哪個SOR可以透過 "nvidia,dc-connector"這個property做切換.
所以你要使用nvdisplay@15200000, nvdisplay@15210000, nvdisplay@15220000 都沒有關係, 務必確認 nvidia,dc-connector指到的是你有接hdmi的那個sor.