Commen=
t # 7
on bug 11083=
0
from <=
span class=3D"fn">Marcin Zajaczkowski
(In reply to Ilia Mirkin from comment #6)
> (In reply to Marcin Zajaczkowski from comment #4)
> > Of course it didn't make sense to turn it on, as it was already t=
urned on
> > (DynPwr) in my case :) ). I can switch it off with vgaswitcheroo =
(or at
> > least to be reported as DynOff - I will check it later with power=
top) when
> > no external output is connected. And what I missed in my previous=
comment -
> > the external monitor works out-of-box, which is nice progress.
>=20
> vgaswitcheroo explicit control is for hard muxes. These were popular 2=
005 to
> 2010 or so. You just have 2 GPUs. vgaswitcheroo reports whether they'r=
e on
> or off, but that control is performed dynamically by the driver based =
on
> usage.
You are right. Afew seconds after an external monitor is disconnected the
discrete card becomes DynOff.
I have a hard mux in my (quite) old Asus. I can use only the Intel card to =
save
energy and the Nvidia card is used only occasionally for CUDA and gaming. I
wonder why in multiple laptops nowadays the outputs are wired to one card
limiting the aforementioned use case? What are the benefits of that (assumi=
ng
the modern Intel can handle 3 displays enabled at the same time)?
> > There are also no reported providers in xra=
ndr:
> > > $ xrandr --listproviders
> > > Providers: number: 0
>=20
> This is incredibly odd -- there must always be at least 1! Are you run=
ning
> Xwayland or something? If so, the displays would be controlled through=
your
> wayland compositor. You can check that kms is working:
Yes, it was Wayland. With Xorg I see two providers:
> Providers: number : 2
> Provider 0: id: 0x6b cap: 0xf, Source Output, Sink Output, Source Offl=
oad, Sink Offload crtcs: 3 outputs: 3 associated providers: 1 name:modesett=
ing
> Provider 1: id: 0x45 cap: 0x2, Sink Output crtcs: 4 outputs: 2 associa=
ted providers: 1 name:modesetting
Hmm, why there are 3 and 4 outputs associated to them? Is it possible that =
DP
output is accessible with the Intel card only (I don't have a connector rig=
ht
here to test it organoleptically)?
>=20
> grep . /sys/class/drm/card*-*/status
>=20
> You should see some card0-* and card1-* entries.
Yes, I see different outputs.
> /sys/class/drm/card0-DP-1/status:disconnected
> /sys/class/drm/card0-eDP-1/status:connected
> /sys/class/drm/card0-HDMI-A-1/status:disconnected
> /sys/class/drm/card1-DP-2/status:disconnected
> /sys/class/drm/card1-HDMI-A-2/status:disconnected