Hi Takashi, > -----Original Message----- > From: Takashi Iwai [mailto:tiwai@xxxxxxx] > Sent: Wednesday, March 02, 2016 3:44 PM > To: libin.yang@xxxxxxxxxxxxxxx > Cc: intel-gfx@xxxxxxxxxxxxxxxxxxxxx; conselvan2@xxxxxxxxx; > jani.nikula@xxxxxxxxxxxxxxx; ville.syrjala@xxxxxxxxxxxxxxx; Vetter, Daniel; > tiwai@xxxxxxx; Yang, Libin > Subject: Re: [PATCH] drm/i915: add audio_ptr pointer check > > On Wed, 02 Mar 2016 03:24:31 +0100, > libin.yang@xxxxxxxxxxxxxxx wrote: > > > > From: Libin Yang <libin.yang@xxxxxxxxxxxxxxx> > > > > check to make sure audio_ptr is not NULL before > > using it. > > I don't think non-NULL is mandatory. If any invalid access is seen, > it should be fixed rather in the audio side. When I enable MST with other patches (not submitted so far), I found system may be random hang when boot up. After apply this patch and another patch (I sent the patch in ALSA Mail list: ALSA: hda - hdmi defer to register acomp eld notifier), the hang issue is fixed. I make the patch because in sound driver side, setting audio_ptr and audio_ops is not in the lock. I'm wondering that the compiler or CPU may optimize and change the setting order (the gfx code and alsa code may run parallelly?). Regards, Libin > > > thanks, > > Takashi > > > > > Signed-off-by: Libin Yang <libin.yang@xxxxxxxxxxxxxxx> > > --- > > drivers/gpu/drm/i915/intel_audio.c | 6 ++++-- > > 1 file changed, 4 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/intel_audio.c > b/drivers/gpu/drm/i915/intel_audio.c > > index 31f6d21..667596d 100644 > > --- a/drivers/gpu/drm/i915/intel_audio.c > > +++ b/drivers/gpu/drm/i915/intel_audio.c > > @@ -529,7 +529,8 @@ void intel_audio_codec_enable(struct > intel_encoder *intel_encoder) > > intel_dig_port->audio_connector = connector; > > mutex_unlock(&dev_priv->av_mutex); > > > > - if (acomp && acomp->audio_ops && acomp->audio_ops- > >pin_eld_notify) > > + if (acomp && acomp->audio_ops && acomp->audio_ops- > >pin_eld_notify && > > + acomp->audio_ops->audio_ptr) > > acomp->audio_ops->pin_eld_notify(acomp->audio_ops- > >audio_ptr, (int) port); > > } > > > > @@ -556,7 +557,8 @@ void intel_audio_codec_disable(struct > intel_encoder *intel_encoder) > > intel_dig_port->audio_connector = NULL; > > mutex_unlock(&dev_priv->av_mutex); > > > > - if (acomp && acomp->audio_ops && acomp->audio_ops- > >pin_eld_notify) > > + if (acomp && acomp->audio_ops && acomp->audio_ops- > >pin_eld_notify && > > + acomp->audio_ops->audio_ptr) > > acomp->audio_ops->pin_eld_notify(acomp->audio_ops- > >audio_ptr, (int) port); > > } > > > > -- > > 1.9.1 > > _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
