On Thu, Aug 15, 2019 at 10:37 AM Alex Deucher <alexdeucher@xxxxxxxxx> wrote: > > On Thu, Aug 15, 2019 at 10:25 AM Karol Herbst <kherbst@xxxxxxxxxx> wrote: > > > > On Thu, Aug 15, 2019 at 4:20 PM <Mario.Limonciello@xxxxxxxx> 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. > > > > > > > > > > > We already have the PRIME offloading in place and if that's not > > > > enough, we should work on extending it, not adding some ACPI based > > > > workarounds, because that's exactly how that looks like. > > > > > > > > Also, was this discussed with anybody involved in the drm subsystem? > > > > > > > > > > > > > > I feel we need a knob and/or DMI detection to affect the changes that the ASL > > > > > normally performs. > > > > > > > > Why do we have to do that on a firmware level at all? > > > > > > Folks from AMD Graphics team recommended this approach. From their perspective > > > it's not a workaround. They view this as a different architecture for AMD graphics driver on > > > Windows and AMD graphics w/ amdgpu driver. They have different ASL paths used for > > > each. > > > > @alex: is this true? > > I'm not familiar with this patches in particular, but I know we've > done things with OEM programs to support Linux on platforms where > Linux support is lacking for in new features for the target distros. > E.g., when the first hybrid graphics laptops were coming out, Linux > didn't support it too well or at all depending on the timing, so the > bios exposed power express which was working well at the time if the > OS told ACPI it was Linux. FWIW, windows does something similar. I don't think windows 7 supports hybrid graphics either so if the OS tells ACPI it's windows 7, it gets power express instead of hybrid graphics as well. At least on laptops that support windows 7 in the first place. Alex > > Alex _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
