Re: 4.20.7: pl2303 not working (post-4.19 regression) (limited info so far, not yet bisected)

From: Nix
Date: Sun Feb 17 2019 - 14:14:02 EST


On 16 Feb 2019, Greg KH told this:

> On Sat, Feb 16, 2019 at 04:26:30PM +0000, Nix wrote:
>> So I just tried to connect up to my ancient Soekris firewall's serial
>> console to try to bisect a problem where it stopped booting in 4.20, and
>> found I couldn't.
>>
>> minicom says:
>>
>> minicom: cannot open /dev/ttyUSB0: Input/output error
>>
>> and in the dmesg we see
>>
>> [705576.028170] pl2303 ttyUSB0: failed to submit interrupt urb: -28
>>
>> Booting to 4.19, everything works fine. (A random GalliumOS Chromebook
[...]
>
> bisection would be great, thanks!

Rrrg. This is going to be harder than I thought. Rebooting, everything
works fine! So this is something that kicks in after something less than
eight days uptime, consistently on every box I own, but is fine on
reboot.

I'm still fairly sure this is a regression -- my machines are often up
for a lot longer than that and I've never seen this before I upgraded to
4.20.x -- but I don't think I'm going to identify it by mindless
bisection. I might have to actually *think* about it.