答复: 答复: [alsa-devel] 答复: [PATCH] vgaswitchroo: set audio client id according to bound gpu client id

[Takashi Iwai]

On Wed, 11 Jul 2018 11:26:11 +0200,
jimqu wrote:
> 
> 
> 
> On 2018年07月11日 17:04, Takashi Iwai wrote:
> > On Wed, 11 Jul 2018 10:41:38 +0200,
> > jimqu wrote:
> >>
> >>
> >> On 2018年07月11日 15:19, Takashi Iwai wrote:
> >>> On Tue, 10 Jul 2018 13:21:00 +0200,
> >>> Takashi Iwai wrote:
> >>>>> revert the fix of amdgpu suspend issue, audio issue also can be observed.
> >>>> Did you check the behavior with the single AMD GPU hardware?
> >>>> If confirmed, we can forget about vga_switcheroo.
> >>> ... and taking a look back at the recent changes, I guess it can be
> >>> the forced runtime PM enablement, not directly with vga_switcheroo
> >>> action itself.
> >> Yeah, the function vga_switcheroo_set_dynamic_switch() has discarded,
> >> so there is no way GFX driver to control audio power. However, keep in
> >> mind, current audio is bound to iGPU, that mean the issue should be
> >> nothing about
> >> vgaswtichreoo. since current audio pci bus is different from dGPU,
> >> that means the pci_bus_set_current_state() in
> >> vga_switcheroo_runtime_suspend() and pci_wakeup_bus() in
> >> vga_switcheroo_runtime_resume() could not touch the audio pci power
> >> state from dGPU instance.
> >>
> >> This is a feedback got from our OEM developer, it is the overview of
> >> audio detect process.
> >>
> >>> First, the kernel  audio driver will be triggered to read ELD, if the
> >>>> ELD is valid, it will report a jack event (on or available) to sound
> >>>> core driver; the pulseaudio subscribe all jack events, if it is told
> >>>> that the hdmi jack is plugged in (on), the pulseaudio will set this
> >>>> port to available, then the pa-card or pa-sink has available port, it
> >>>> can be selected (manually, some daemons or policy in
> >>>> /usr/share/pulseaudio/alsa-mixer/) as default output card/default sink.
> >> If the description is correct. I think there are maybe two problems.
> >>
> >> 1. audio will auto power off after setup device link duo to usage_count=0.
> >> 2. duo to audio is power down, it could not get the HDMI jack insert event.
> >>
> >> How do you think?
> >>
> >>> Jim, could you tell me which PCI devices are handled as vga_switcheroo
> >>> audio client?  The kernel should show all messages "xxx: Handle
> >>> vga_switcheroo audio client".
> >> [    4.311095] snd_hda_intel 0000:06:00.1: enabling device (0000 -> 0002)
> >> [    4.314286] snd_hda_intel 0000:06:00.1: Handle vga_switcheroo audio
> >> client
> >> [    4.314822] snd_hda_intel 0000:06:00.6: enabling device (0000 -> 0002)
> >>
> >> 01:00.0 VGA compatible controller [0300]: Advanced Micro Devices,
> >> Inc. [AMD/ATI] Device [1002:699f] (rev c3)
> >> 06:00.0 VGA compatible controller [0300]: Advanced Micro Devices,
> >> Inc. [AMD/ATI] Device [1002:15dd] (rev d1)
> >> 06:00.1 Audio device [0403]: Advanced Micro Devices, Inc. [AMD/ATI]
> >> Device [1002:15de]
> > OK this sheds a brighter light, finally.
> >
> > If my understanding is correct, the issue is a false vga_switcheroo
> > audio detection, after all.  This is the primary GPU and it shouldn't
> > be registered as a vga_switcheroo discrete GPU.
> >
> > Below is a very ugly workaround for this particular case.  It assumes
> > that the AMD+AMD combo will never have audio outputs on both but only
> > for the primary, and it's possibly wrong.
> >
> > Is there a handy way to identify whether the given VGA PCI entry is
> > a discrete GPU or not?  The amdgpu and radeon seem checking ATPX
> > ACPI.
> 
> This is no issue about this topic, in amdgpu driver, both iGPU/dGPU
> will register as VGA_SWITCHEROO_UNKNOWN_ID, and the client id will be
> re-initialized in vgaswitchreoo_enable() via ATPX call. Then, iGPU
> will set as VGA_SWITCHEROO_IGD, and dGPU will set as
> VGA_SWITCHEROO_DIS.

Please check the patch.  It's not about AMDGPU driver but the vga
switcheroo detection in HD-audio driver.  Not the GPU side but the
audio side.

The issues are two folds:
- We register each AMD controller associated with a GPU always as a
  discrete GPU vga_switcheroo audio.
- And when it's registered as a vga_switcheroo client, we forcibly
  enable runtime PM of the controller, since discrete GPU needs the
  runtime suspend.

So a workaround in your case is just not to register as a vga
switcheroo audio client.  Then the runtime PM isn't enabled in the AMD
HDMI audio controller, and the HDMI detection remains active.


Takashi

> 
> Thanks
> JimQu
> >
> > Takashi
> >
> > ---
> > --- a/sound/pci/hda/hda_intel.c
> > +++ b/sound/pci/hda/hda_intel.c
> > @@ -1418,8 +1418,18 @@ static int azx_dev_free(struct snd_device *device)
> >    */
> >   static struct pci_dev *get_bound_vga(struct pci_dev *pci)
> >   {
> > +	static const struct pci_device_id ids[] = {
> > +		{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_ANY_ID),
> > +		  .class = PCI_BASE_CLASS_DISPLAY << 16,
> > +		  .class_mask = 0xff << 16 },
> > +		{}
> > +	};
> >   	struct pci_dev *p;
> >   +	/* check whether Intel graphics is present as primary GPU */
> > +	if (!pci_dev_present(ids))
> > +		return NULL;
> > +
> >   	/* check only discrete GPU */
> >   	switch (pci->vendor) {
> >   	case PCI_VENDOR_ID_ATI:
>