On Tue, 06 Oct 2020 18:17:22 +0200, Kai Vehmanen wrote: > > From: Takashi Iwai <tiwai@xxxxxxx> > > Current hdac_i915 uses a static completion instance to wait > for i915 driver to complete the component bind. > > This design is not safe if multiple HDA controllers are active and > communicating with different i915 instances, and can lead to list > corruption and failed audio driver probe. > > Fix the design by moving completion mechanism to common acomp > code and remove the related code from hdac_i915. > > Co-developed-by: Kai Vehmanen <kai.vehmanen@xxxxxxxxxxxxxxx> > Signed-off-by: Kai Vehmanen <kai.vehmanen@xxxxxxxxxxxxxxx> > Signed-off-by: Takashi Iwai <tiwai@xxxxxxx> Now I applied it with Fixes tag to 7b882fe3e3e8 ("ALSA: hda - handle multiple i915 device instances"). thanks, Takashi > --- > include/drm/drm_audio_component.h | 4 ++++ > sound/hda/hdac_component.c | 3 +++ > sound/hda/hdac_i915.c | 23 +++-------------------- > 3 files changed, 10 insertions(+), 20 deletions(-) > > diff --git a/include/drm/drm_audio_component.h b/include/drm/drm_audio_component.h > index a45f93487039..0d36bfd1a4cd 100644 > --- a/include/drm/drm_audio_component.h > +++ b/include/drm/drm_audio_component.h > @@ -117,6 +117,10 @@ struct drm_audio_component { > * @audio_ops: Ops implemented by hda driver, called by DRM driver > */ > const struct drm_audio_component_audio_ops *audio_ops; > + /** > + * @master_bind_complete: completion held during component master binding > + */ > + struct completion master_bind_complete; > }; > > #endif /* _DRM_AUDIO_COMPONENT_H_ */ > diff --git a/sound/hda/hdac_component.c b/sound/hda/hdac_component.c > index 89126c6fd216..bb37e7e0bd79 100644 > --- a/sound/hda/hdac_component.c > +++ b/sound/hda/hdac_component.c > @@ -210,12 +210,14 @@ static int hdac_component_master_bind(struct device *dev) > goto module_put; > } > > + complete_all(&acomp->master_bind_complete); > return 0; > > module_put: > module_put(acomp->ops->owner); > out_unbind: > component_unbind_all(dev, acomp); > + complete_all(&acomp->master_bind_complete); > > return ret; > } > @@ -296,6 +298,7 @@ int snd_hdac_acomp_init(struct hdac_bus *bus, > if (!acomp) > return -ENOMEM; > acomp->audio_ops = aops; > + init_completion(&acomp->master_bind_complete); > bus->audio_component = acomp; > devres_add(dev, acomp); > > diff --git a/sound/hda/hdac_i915.c b/sound/hda/hdac_i915.c > index 5f0a1aa6ad84..454474ac5716 100644 > --- a/sound/hda/hdac_i915.c > +++ b/sound/hda/hdac_i915.c > @@ -11,8 +11,6 @@ > #include <sound/hda_i915.h> > #include <sound/hda_register.h> > > -static struct completion bind_complete; > - > #define IS_HSW_CONTROLLER(pci) (((pci)->device == 0x0a0c) || \ > ((pci)->device == 0x0c0c) || \ > ((pci)->device == 0x0d0c) || \ > @@ -130,19 +128,6 @@ static bool i915_gfx_present(void) > return pci_dev_present(ids); > } > > -static int i915_master_bind(struct device *dev, > - struct drm_audio_component *acomp) > -{ > - complete_all(&bind_complete); > - /* clear audio_ops here as it was needed only for completion call */ > - acomp->audio_ops = NULL; > - return 0; > -} > - > -static const struct drm_audio_component_audio_ops i915_init_ops = { > - .master_bind = i915_master_bind > -}; > - > /** > * snd_hdac_i915_init - Initialize i915 audio component > * @bus: HDA core bus > @@ -163,9 +148,7 @@ int snd_hdac_i915_init(struct hdac_bus *bus) > if (!i915_gfx_present()) > return -ENODEV; > > - init_completion(&bind_complete); > - > - err = snd_hdac_acomp_init(bus, &i915_init_ops, > + err = snd_hdac_acomp_init(bus, NULL, > i915_component_master_match, > sizeof(struct i915_audio_component) - sizeof(*acomp)); > if (err < 0) > @@ -177,8 +160,8 @@ int snd_hdac_i915_init(struct hdac_bus *bus) > if (!IS_ENABLED(CONFIG_MODULES) || > !request_module("i915")) { > /* 60s timeout */ > - wait_for_completion_timeout(&bind_complete, > - msecs_to_jiffies(60 * 1000)); > + wait_for_completion_timeout(&acomp->master_bind_complete, > + msecs_to_jiffies(60 * 1000)); > } > } > if (!acomp->ops) { > -- > 2.28.0 >