On Tue, 27 Aug 2019 15:47:56 +0200, Kai-Heng Feng 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
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);
Oh, right now I have a fix patch to submit for turning on the runtime PM behavior upon the audio component registration, essentially for amdgpu and nouveau. My fix includes the movement of this flag into hda_bus object, so this patch would become inapplicable (although it's trivial).
So I can apply this patch with the correction to sound git tree if the first patch gets ack from PCI maintainers (and they agree to apply over sound git tree).
In anyway, I'm going to post my patch that will conflict with this.
thanks,
Takashi