Re: [Nouveau] [PATCH 1/7] Revert "ACPI / OSI: Add OEM _OSI string to enable dGPU direct output"

[Takashi Iwai <tiwai@suse.de>]

On Thu, 15 Aug 2019 18:19:52 +0200,
<Mario.Limonciello@dell.com> wrote:
> 
> > -----Original Message-----
> > From: Takashi Iwai <tiwai@suse.de>
> > Sent: Thursday, August 15, 2019 9:57 AM
> > To: Alex Deucher
> > Cc: Karol Herbst; Limonciello, Mario; nouveau; Rafael J . Wysocki; LKML; dri-devel;
> > Linux ACPI Mailing List; Alex Hung; Ben Skeggs; David Airlie
> > Subject: Re: [Nouveau] [PATCH 1/7] Revert "ACPI / OSI: Add OEM _OSI string to
> > enable dGPU direct output"
> > 
> > 
> > [EXTERNAL EMAIL]
> > 
> > On Thu, 15 Aug 2019 16:37:05 +0200,
> > Alex Deucher wrote:
> > >
> > > On Thu, Aug 15, 2019 at 10:25 AM Karol Herbst <kherbst@redhat.com> wrote:
> > > >
> > > > On Thu, Aug 15, 2019 at 4:20 PM <Mario.Limonciello@dell.com> wrote:
> > > > >
> > > > > > > There are definitely going to be regressions on machines in the field
> > with the
> > > > > > > in tree drivers by reverting this.  I think we should have an answer for all
> > of
> > > > > > those
> > > > > > > before this revert is accepted.
> > > > > > >
> > > > > > > Regarding systems with Intel+NVIDIA, we'll have to work with partners
> > to
> > > > > > collect
> > > > > > > some information on the impact of reverting this.
> > > > > > >
> > > > > > > When this is used on a system with Intel+AMD the ASL configures AMD
> > GPU to
> > > > > > use
> > > > > > > "Hybrid Graphics" when on Windows and "Power Express" and
> > "Switchable
> > > > > > Graphics"
> > > > > > > when on Linux.
> > > > > >
> > > > > > and what's exactly the difference between those? And what's the actual
> > > > > > issue here?
> > > > >
> > > > > DP/HDMI is not detected unless plugged in at bootup.  It's due to missing
> > HPD
> > > > > events.
> > > > >
> > > >
> > > > afaik Lyude was working on fixing all that, at least for some drivers.
> > > > If there is something wrong, we still should fix the drivers, not
> > > > adding ACPI workarounds.
> > > >
> > > > Alex: do you know if there are remaining issues regarding that with amdgpu?
> > >
> > > There was an issue with hpd events not making it to the audio side
> > > when things were powered down that was fixed with this patch set:
> > > https://patchwork.freedesktop.org/patch/316793/
> > > Those patches depended on a bunch of alsa changes as well which may
> > > have not been available in the distro used for a particular OEM
> > > program.
> > 
> > FYI, the corresponding commit for ALSA part is destined for 5.4
> > kernel:
> > 
> > https://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound.git/commit/?id=ade
> > 49db337a9d44ac5835cfce1ee873549011b27
> > 
> > BTW, Nouveau should suffer from the same problem.  The patch to add
> > the audio component support is found at:
> >   https://patchwork.freedesktop.org/patch/319131/
> > 
> > 
> 
> It sounds like 5.3rcX won't be a useful check then.

For HDMI/DP audio, right, the main pieces are still missing in 5.3.
But there is no regression in this regard, OTOH.

> So am I correct to understand that everything related to the AMD failures
> described in this thread should be in linux-next at this point?

I'm not sure what you're referring as "AMD failures", so leave this
question to AMD people :)


Takashi