[Intel-gfx] Intel Arc A370M vs Linux 5.19

[Daniel J Blueman]

On Fri, 16 Sept 2022 at 00:35, Tvrtko Ursulin
<tvrtko.ursulin at linux.intel.com> wrote:
>> On 15/09/2022 15:54, Rodrigo Vivi wrote:
> > On Thu, Sep 15, 2022 at 10:40:59PM +0800, Daniel J Blueman wrote:
> >> On Thu, 15 Sept 2022 at 22:09, Rodrigo Vivi <rodrigo.vivi at intel.com> wrote:
> >>> On Thu, Sep 15, 2022 at 09:08:08PM +0800, Daniel J Blueman wrote:
> >>>> Dear Intel et al,
> >>>>
> >>>> With a HP Spectre x360 16 16-f1xxx/891D (Intel i7-1260P) with an Arc
> >>>> A370M GPU [1] running the latest Ubuntu 22.10 5.19.0-15-generic
> >>>> kernel, we see:
> >>>>
> >>>> i915 0000:03:00.0: Your graphics device 5693 is not properly supported
> >>>> by the driver in this kernel version. To force driver probe anyway,
> >>>> use i915.force_probe=5693
> >>>>
> >>>> Since the GPU is unmanaged, battery life is around 30% of what it
> >>>> could be. Unsurprisingly, adding i915.force_probe=5693 causes
> >>>> additional  issues. Given a lack of BIOS option to disable the GPU, is
> >>>> there any advice for Linux support or at least putting the GPU into
> >>>> D3? I see only Windows drivers on the official support page [2], and
> >>>> Linux 6.0-rc5 isn't buildable [3].
> >>>
> >>> I believe this is what you are looking for:
> >>>
> >>> echo auto | sudo tee /sys/bus/pci/devices/0000\:03\:00.0/power/control
> >>>
> >>> In Linux the default is to keep the unmanaged devices in D0.
> >>> But changing the rpm to auto should transition the device to D3.
> >>>
> >>> You can go further and check with the lspci -vv if there are other
> >>> unmanaged devices in the same pci root tree and also add them to the
> >>> 'auto' rpm so you can even achieve D3cold in that whole device, what
> >>> gives you extra power savings.
> >>>
> >>> I hope this helps for now.
> >>
> >> Yes, I was also hoping this would work as we see D3hot is supported:
> >>
> >> # echo auto > /sys/bus/pci/devices/0000\:03\:00.0/power/control
> >> # lspci -vvvs 03:00.0
> >> ...
> >> Capabilities: [d0] Power Management version 3
> >>          Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA
> >> PME(D0+,D1-,D2-,D3hot+,D3cold-)
> >>          Status: D0 NoSoftRst+ PME-Enable- DSel=0 DScale=0 PME-
> >>                  ^^
> >>
> >> However it stays in D0 with PME disabled as we see. "Kernel modules:
> >> i915" may suggest the i915 driver holds a reference to it, preventing
> >> the transition.
> >
> > Oh, yes. I was thinking more on using the command line I sent when
> > the i915 is not probed. i.e. without using the force probe. your first
> > scenario.
>
> Could it help to bind DG2 to vfio-pci and so prevent i915 touching it?

Bingo! Booting with vfio-pci.ids=8086:5693 in my case left the dGPU in
D3, giving the expected battery runtime.

Many thanks Tvrtko,
  Dan
-- 
Daniel J Blueman