[alsa-devel] [PATCH RFC/untested] hda-intel: suspend HDA codecs and the PCI device in error cases

[Guennadi Liakhovetski]

Hi Takashi,

On Fri, 8 Feb 2019, Takashi Iwai wrote:

> On Fri, 08 Feb 2019 11:50:25 +0100,
> Guennadi Liakhovetski wrote:
> > 
> > From: Guennadi Liakhovetski <guennadi.liakhovetski at linux.intel.com>
> > 
> > If HDA probing on Intel platforms fails, all the devices, that have
> > previously been powered up, have to be suspended again.
> > 
> > Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski at linux.intel.com>
> > ---
> > 
> > I came across HDA not suspending when no codec driver has successfully 
> > probed while working on SOF. Then I decided to look how this is handled in 
> > the mainline Intel HDA code and I think something like this patch is 
> > needed, however, I don't have a set up to test it. I haven't looked at the 
> > tegra HDA implementation, possibly they need something similar. Please, 
> > comment.
> 
> This will likely lead to the runtime PM refcount unbalance at
> azx_free(), I'm afraid.  chip->running is used as a flag to judge
> whether the runtime PM is applied or not, and if you jump to the error
> path, the flag won't be set.

Ok, understand, indeed, that would be a problem now. But isn't that also a 
problem, if azx_probe_continue() doesn't run at all before the azx_free()? 
Wouldn't this fix it?

@@ -1300,7 +1300,7 @@ static int azx_free(struct azx *chip)
 	struct hda_intel *hda = container_of(chip, struct hda_intel, chip);
 	struct hdac_bus *bus = azx_bus(chip);
 
-	if (azx_has_pm_runtime(chip) && chip->running)
+	if (azx_has_pm_runtime(chip))
 		pm_runtime_get_noresume(&pci->dev);
 	chip->running = 0;
 

Thanks
Guennadi

> thanks,
> 
> Takashi
> 
> > 
> >  sound/pci/hda/hda_intel.c | 9 +++++----
> >  1 file changed, 5 insertions(+), 4 deletions(-)
> > 
> > diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
> > index e784130..d3caa37 100644
> > --- a/sound/pci/hda/hda_intel.c
> > +++ b/sound/pci/hda/hda_intel.c
> > @@ -2229,14 +2229,14 @@ static int azx_probe_continue(struct azx *chip)
> >  	/* create codec instances */
> >  	err = azx_probe_codecs(chip, azx_max_codecs[chip->driver_type]);
> >  	if (err < 0)
> > -		goto out_free;
> > +		goto out_power_down;
> >  
> >  #ifdef CONFIG_SND_HDA_PATCH_LOADER
> >  	if (chip->fw) {
> >  		err = snd_hda_load_patch(&chip->bus, chip->fw->size,
> >  					 chip->fw->data);
> >  		if (err < 0)
> > -			goto out_free;
> > +			goto out_power_down;
> >  #ifndef CONFIG_PM
> >  		release_firmware(chip->fw); /* no longer needed */
> >  		chip->fw = NULL;
> > @@ -2246,12 +2246,12 @@ static int azx_probe_continue(struct azx *chip)
> >  	if ((probe_only[dev] & 1) == 0) {
> >  		err = azx_codec_configure(chip);
> >  		if (err < 0)
> > -			goto out_free;
> > +			goto out_power_down;
> >  	}
> >  
> >  	err = snd_card_register(chip->card);
> >  	if (err < 0)
> > -		goto out_free;
> > +		goto out_power_down;
> >  
> >  	setup_vga_switcheroo_runtime_pm(chip);
> >  
> > @@ -2260,6 +2260,7 @@ static int azx_probe_continue(struct azx *chip)
> >  
> >  	set_default_power_save(chip);
> >  
> > +out_power_down:
> >  	if (azx_has_pm_runtime(chip))
> >  		pm_runtime_put_autosuspend(&pci->dev);
> >  
> > -- 
> > 1.9.3
> > 
> > 
>