Messages in this thread | | | Subject | Re: [PATCH 2/2] ALSA: hda: Allow HDA to be runtime suspended when dGPU is not bound | From | Kai-Heng Feng <> | Date | Tue, 27 Aug 2019 22:50:03 +0800 |
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at 21:47, Kai-Heng Feng <kai.heng.feng@canonical.com> wrote:
> It's a common practice to let dGPU unbound and use PCI port PM to > disable its power through _PR3. When the dGPU comes with an HDA > function, the HDA won't be suspended if the dGPU is unbound, so the dGPU > power can't be disabled. > > Commit 37a3a98ef601 ("ALSA: hda - Enable runtime PM only for > discrete GPU") only allows HDA to be runtime-suspended once GPU is > bound, to keep APU's HDA working. > > However, HDA on dGPU isn't that useful if dGPU is unbound. So let relax > the runtime suspend requirement for dGPU's HDA function, to save lots of > power. > > BugLink: https://bugs.launchpad.net/bugs/1840835 > Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com> > —
Forgot to mention that for some platforms this issue happen after commit b516ea586d71 ("PCI: Enable NVIDIA HDA controllers”) which starts to unhide the “hidden” HDA.
Kai-Heng
> sound/pci/hda/hda_intel.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c > index 99fc0917339b..d4ee070e1a29 100644 > --- a/sound/pci/hda/hda_intel.c > +++ b/sound/pci/hda/hda_intel.c > @@ -1285,7 +1285,8 @@ static void init_vga_switcheroo(struct azx *chip) > dev_info(chip->card->dev, > "Handle vga_switcheroo audio client\n"); > hda->use_vga_switcheroo = 1; > - hda->need_eld_notify_link = 1; /* cleared in gpu_bound op */ > + /* cleared in gpu_bound op */ > + hda->need_eld_notify_link = !pci_pr3_present(p); > chip->driver_caps |= AZX_DCAPS_PM_RUNTIME; > pci_dev_put(p); > } > -- > 2.17.1
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