Re: Kernel 5.10 USB issues

On Wed, Nov 24, 2021 at 11:46:06AM +1100, Jupiter wrote:

Hi,

I connected a USB bus between an iMX6ULZ and an 4G LTE modem, it was
running well in kernel 4.19.75. I've just upgraded kernel to 5.10.59,
the USB is broken, the USB drivers were disconnected / connected
repeatedly:

[12781.730889] usb 1-1: USB disconnect, device number 84
[12781.808317] option1 ttyUSB0: GSM modem (1-port) converter now
disconnected from ttyUSB0

That is usually a hardware problem, the kernel can not disconnect a
device from the bus through software.

But, if 4.19 is working, can you use 'git bisect' between the two
kernels to find what caused the problem?

thanks,

greg k-h