AM4378: Reset USB module from disconnection caused by ESD

Hi Tony,

The log seems telling there are multiple USB devices are attached. Please explain the USB topology on this system.

Hi Bin,

USB0+ WIFI module; 

USB1+ 4 port HUB.

Did not connect device on HUB during ESD test, and USB1 is not impacted by ESD test when USB0 failed, can access U-flash on USB1 HUB.

Tony,

What is USB0 dr_mode setting in kernel device tree, host or otg?

Bin，

it is host

attach the USB0 schematic also

Hi Tony,

The SDK7.3 is no longer supported, by please try if unload then reload the USB driver can recover the issue.

# modprobe -r dwc3_omap

# modprobe dwc3_omap

Hi Bin,

It works.

But it reset both USB0 and USB1, result in USB1 disconnected also, as USB1 connects a HUB, it will impact other modules, is there a command to reset USB0 only?

Hi Tony,

Glad to heard this can resolve the issue.

Yes, there is a way to reset USB0 only, you can do the dwc3_omap driver unbind then bind through Linux sysfs. Please let me know if you don't know the exact command, I will have to test it on my AM437x EVM to provide the exact command.

Hi Bin,

We don't know, need you help on exact commands.