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

[Takashi Iwai]

On Fri, 08 Feb 2019 12:33:14 +0100,
Guennadi Liakhovetski wrote:
> 
> 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()? 

In that case, it won't go suspend, so it won't need resume at that
point.

> Wouldn't this fix it?

Not really.  The chip->running is also checked in azx_runtime_idle().

Also, what you're trying to change is the behavior of HD-audio
controller, not about codecs.


thanks,

Takashi

> @@ -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
> > > 
> > > 
> > 
>