Re: Issues with USB-C external monitors

On 01.12.2020 17:10, myfreeweb wrote:
> >> __snippet__
> >> res = drmModeGetResources(fd);
> >> for (int i = 0; i < res->count_connectors; ++i) {
> >>     conn = drmModeGetConnector(fd, res->connectors[i]);
>
> Note: you can run graphics/drm_info instead of writing custom code.

Thanks for the tip.

> devd (really drm in the kernel) provides hotplug events (system DRM, type HOTPLUG).
> libudev-devd translates these to UD_ACTION_HOTPLUG.
> This works well with wlroots compositors at least.
>
> How xorg does this I have no idea, as I don't use xorg.
> If your xorg is built with DEVD instead of UDEV option, it shouldn't work, I don't recall anyone adding support for that there.
> With UDEV it might work?

On current, for now I'm using the standard xorg-server from pkg, built
with UDEV according to [1], so apparently that is not working either. At
least in my case.

Will dig futher into it.

>
> >There is missing code in the kernel to handle USB-C PCI express
> >attach/detach. CC'ing Scott Long.
>
> Seems like this is about regular DisplayPort over USB-C (the USB side almost always handled in firmware for this on non-embedded computers).
> I don't think I've ever seen a *monitor* connecting over PCIe to an existing GPU ;)
> (in this case card0, the onboard vega)

Yes, this is just the DisplayPort over USB-C from the onboard vega GPU.

[1] https://www.freshports.org/x11-servers/xorg-server/