[alsa-devel] [PATCH] ALSA: hda - Fix race between PM ops and HDA init/probe

[Eoff, Ullysses A]

> -----Original Message-----
> From: Takashi Iwai [mailto:tiwai at suse.de]
> Sent: Wednesday, July 29, 2015 12:03 AM
> To: Eoff, Ullysses A
> Cc: alsa-devel at alsa-project.org; Lee, Zhuo-hao; Yang, Libin; dgreid at chromium.org
> Subject: Re: [PATCH] ALSA: hda - Fix race between PM ops and HDA init/probe
> 
> On Tue, 28 Jul 2015 22:29:56 +0200,
> U. Artie Eoff wrote:
> >
> > PM ops could be triggered before HDA is done initializing
> > and cause PM to set HDA controller to D3Hot.  This can result
> > in "CORB reset timeout#2, CORBRP = 65535" and "no codecs
> > initialized".  Additionally, PM ops can be triggered before
> > azx_probe_continue finishes (async probe).  This can result
> > in a NULL deref kernel crash.
> >
> > To fix this, avoid PM ops if !chip->running.
> >
> > Signed-off-by: U. Artie Eoff <ullysses.a.eoff at intel.com>
> > ---
> >  sound/pci/hda/hda_intel.c | 6 +++---
> >  1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
> > index 735bdcb04ce8..c38c68f57938 100644
> > --- a/sound/pci/hda/hda_intel.c
> > +++ b/sound/pci/hda/hda_intel.c
> > @@ -867,7 +867,7 @@ static int azx_suspend(struct device *dev)
> >
> >  	chip = card->private_data;
> >  	hda = container_of(chip, struct hda_intel, chip);
> > -	if (chip->disabled || hda->init_failed)
> > +	if (chip->disabled || hda->init_failed || !chip->running)
> 
> This is superfluous, as azx_runtime_idle() returns -EBUSY.
> 

This is the sleep suspend, not runtime.  Runtime idle result does not
influence sleep pm ops.

> >  		return 0;
> >
> >  	bus = azx_bus(chip);
> > @@ -902,7 +902,7 @@ static int azx_resume(struct device *dev)
> >
> >  	chip = card->private_data;
> >  	hda = container_of(chip, struct hda_intel, chip);
> > -	if (chip->disabled || hda->init_failed)
> > +	if (chip->disabled || hda->init_failed || !chip->running)
> 
> Ditto.
> 

Similar here... not runtime.

> 
> Takashi
> 
> >  		return 0;
> >
> >  	if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL
> > @@ -1027,7 +1027,7 @@ static int azx_runtime_idle(struct device *dev)
> >  		return 0;
> >
> >  	if (!power_save_controller || !azx_has_pm_runtime(chip) ||
> > -	    azx_bus(chip)->codec_powered)
> > +	    azx_bus(chip)->codec_powered || !chip->running)
> >  		return -EBUSY;
> >
> >  	return 0;
> > --
> > 2.1.0
> >