USB GPU bugs

[Hans de Goede]

Hi,

On 09-10-2019 12:23, Pekka Paalanen wrote:
> On Wed, 9 Oct 2019 09:59:29 +0200
> Hans de Goede <hdegoede at redhat.com> wrote:

<snip>

>> I think I might also be seeing some variant of your "not enough hotplug
>> events" bug. With the gm12u320 projector when hotplugged it is listed
>> as "unknown" in gnome's display-settings until I change the settings
>> once and then it becomes "Acer" as it should be. I believe that this
>> issue is actually also present in the 1.20 branch.
> 
> In my case, I see an "add" and three HOTPLUG events via udev when I
> hotplug the DisplayLink dock and it creates the DRM device node on the
> spot. Mutter receives just one RandR event though, which it deems is
> not a hotplug, and looking at the config timestamps I think the event
> indeed is reflecting too old state. 'xrandr' will show everything about
> the new connector just fine though, IIRC.

I just realized I should probably respond to this bit. You see that
after "xrandr" everything looks ok, but the "xrandr" command causes
a round trip to the kernel and even causes the kernel to re-poll all
connectors. Have you tried "xrandr --current" ? That will return the
current state stored inside the xserver without re-querying the kernel.

Not sure of this helps, but I thought I should mention it.

Regards,

Hans