| Message ID | 20190827134756.10807-2-kai.heng.feng@canonical.com |
|---|---|
| State | Changes Requested |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | [1/2] PCI: Add a helper to check Power Resource Requirements _PR3 existence | expand |
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
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
On Tue, Aug 27, 2019 at 09:47:56PM +0800, 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. Just a terminology question: I thought "using PCI port PM" meant using the PCI Power Management Capability in config space to directly change the device's power state, e.g., in pci_raw_set_power_state(). And I thought using _PS3, _PR3, etc would be part of "platform power management"? And AFAICT, _PR3 merely returns a list of power resources; it doesn't disable power itself. > 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); > chip->driver_caps |= AZX_DCAPS_PM_RUNTIME; > pci_dev_put(p); > } > -- > 2.17.1 >
Hi Bjorn, at 06:31, Bjorn Helgaas <helgaas@kernel.org> wrote: > On Tue, Aug 27, 2019 at 09:47:56PM +0800, 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. > > Just a terminology question: > > I thought "using PCI port PM" meant using the PCI Power Management > Capability in config space to directly change the device's power > state, e.g., in pci_raw_set_power_state(). What I meant is to use pcieport.ko directly. > > And I thought using _PS3, _PR3, etc would be part of "platform power > management”? Ok, will update the wording. > > And AFAICT, _PR3 merely returns a list of power resources; it doesn't > disable power itself. Yes, through its _PS3 and _OFF. I’ll update the wording. Kai-Heng > >> 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); >> chip->driver_caps |= AZX_DCAPS_PM_RUNTIME; >> pci_dev_put(p); >> } >> -- >> 2.17.1
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); }
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(-)