Armsom cm5, onboard USB hub is disconnected when booting

[tbang]

Hello Dear,

 

After flashing *Armsom-cm5-rpi-cm4-io_*, there is one critical problem.
onboard USB hub always connects and disconnects 2 times when booting.

dmesg outputs:

[ 6.190239] hub 1-1:1.0: USB hub found
…
[ 7.868081] rk-pcie 2a200000.pcie: PCIe Link Fail, LTSSM is 0x3, hw_retries=0
[ 7.868642] usb 1-1: USB disconnect, device number 2
…
[ 9.326443] hub 1-1:1.0: USB hub found
…
[ 11.213062] rk-pcie 2a200000.pcie: PCIe Link Fail, LTSSM is 0x3, hw_retries=1
[ 11.213297] usb 1-1: USB disconnect, device number 4

I have tried with many variations, but the onboard hub is always disconnected.

• server/desktop
• community release/ self build
• several tags from 25.5 to 26.2
• CONFIG_USB_ONBOARD_HUB  O/X
• rpi cm4 io board/ Ochin board

However,

• Armsom's official image has no problem with the onboard usb hub.
• CM4-nano-B has no onboard hub, and has no problem with external hub.

So, it seems to be a SW problem.

 

Please review this problem.

Thanks.

Edited 1 hour ago by tbang

[tbang]

I found the reason. (Different function of Pin 100)

• cm5-io: PCIe_PWR_EN
• rpi-cm4-io: nEXTRST used for USB hub reset

With rpi-cm4-io and no pcie device,

• linux sets PCIe_PWR_EN=0 (turn off pcie)
• But rpi-cm4-io thinks that nEXTRST=0 (always reset usb hub)

 

The temporary solution is:

• For the pause of compile, please turn on kernel config
• When kernel config appears,     sudo vi ./cache/sources/linux-kernel-worktree/6.1__rk35xx__arm64/arch/arm64/boot/dts/rockchip/rk3576-armsom-cm5-rpi-cm4-io.dts
• Add the following fix in order to always turn on pcie

        vcc3v3_pcie0: vcc3v3-pcie0 {
...
                regulator-boot-on;
                regulator-always-on;
                enable-active-high;
...
        };

 

I do not know how the .dts is generated,

so the patch can be made by an expert of Armbian.