[Intel-gfx] Intel Arc A370M vs Linux 5.19

[Rodrigo Vivi]

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.

With the i915 loaded I'd like to see the dmesg and a few of the debugfs
files under: /sys/kernel/debug/dri/0

like: i915_runtime_pm_status, i915_power_domain_info

> 
> Dan
> -- 
> Daniel J Blueman