On Thu, Aug 15, 2019 at 10:15 AM Karol Herbst kherbst@redhat.com wrote:
On Thu, Aug 15, 2019 at 4:13 PM Alex Deucher alexdeucher@gmail.com
wrote:
On Thu, Aug 15, 2019 at 10:04 AM Karol Herbst kherbst@redhat.com wrote:
On Thu, Aug 15, 2019 at 3:56 PM Mario.Limonciello@dell.com wrote:
-----Original Message----- From: linux-acpi-owner@vger.kernel.org <linux-acpi-
owner@vger.kernel.org> On
Behalf Of Dave Airlie Sent: Wednesday, August 14, 2019 5:48 PM To: Karol Herbst Cc: LKML; Linux ACPI; dri-devel; nouveau; Rafael J . Wysocki; Alex Hung;
Ben
Skeggs; Dave Airlie Subject: Re: [Nouveau] [PATCH 1/7] Revert "ACPI / OSI: Add OEM _OSI
string to
enable dGPU direct output"
On Thu, 15 Aug 2019 at 07:31, Karol Herbst kherbst@redhat.com
wrote:
> > This reverts commit 28586a51eea666d5531bcaef2f68e4abbd87242c. > > The original commit message didn't even make sense. AMD _does_
support it and
> it works with Nouveau as well. > > Also what was the issue being solved here? No references to any bugs
and not
> even explaining any issue at all isn't the way we do things. > > And even if it means a muxed design, then the fix is to make it work
inside the
> driver, not adding some hacky workaround through ACPI tricks. > > And what out of tree drivers do or do not support we don't care one
bit anyway.
>
I think the reverts should be merged via Rafael's tree as the original patches went in via there, and we should get them in asap.
Acked-by: Dave Airlie airlied@redhat.com Dave.
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?
Hybrid Graphics is the new "standard" way of handling these laptops. It uses the standard _PR3 APCI method to handle dGPU power. Support for this was added to Linux relatively later compared to when the laptops were launched. "Power Express" used the other AMD specific ATPX ACPI method to handle dGPU power. The driver supports both so either method will work.
Alex
thanks for clarifying. But that still means that we won't need such workarounds for AMD users, right? amdgpu handles hybrid graphics just fine, right?
Yeah it should, assuming you have a new enough kernel which supports HG, which has been several years at this point IIRC.
Alex
Can you define how new of a kernel is a new enough kernel?
Looking on my side these problems were on new hardware (Precision 7740) and are checked as recently as start of this summer, w/ kernel 4.15.
We can arrange to have it checked again on 5.3rcX w/ the OSI disabled.