RE: patch "USB: serial: cp210x: add support for GPIOs on CP2108" added to usb-next

Dear Johan.

Yes, you should be able to apply this patch to older kernels without many additional changes, but you should still mention which kernel you're using >since backporting may not always work as expected.

Yes. Thank you for remaining me.

Good.
Very odd.
Were you using the very same device in both tests? And did you try with the older kernel before the new one? Perhaps the new settings had not yet >taken effect otherwise?

Both test I use same device and same kernel version 5.8.0-59-generic.
May be in the wrong test, the device that have been configuring and the driver may not load new setting from device, I think the wrong may come from device. Just some plug and unplug problem.

quoted

The log written is:
[ 3599.781531] cp210x 2-2.1:1.0: cp2108_gpio_init - 03 00 00 00

Thanks for confirming. So everything appears to work as expected, and you should have seen the expected -EINVAL unless the device actually did return >all-zero here for some reason.

Yes, now it return -EINVAL ("Invalid argument"). As expected.

Thank you.