Messages in this thread | | | Date | Wed, 17 Nov 2021 13:56:14 -0600 | Subject | Re: [greybus-dev] [PATCH] staging: greybus: Add missing rwsem around snd_ctl_remove() calls | From | Alex Elder <> |
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On 11/16/21 1:20 AM, Takashi Iwai wrote: > snd_ctl_remove() has to be called with card->controls_rwsem held (when > called after the card instantiation). This patch adds the missing > rwsem calls around it.
I see the comment above snd_ctl_remove() that says you must hold the write lock. And given that, this seems correct to me.
I understand why you want to take the lock just once, rather than each time snd_ctl_remove() is called.
However I believe the acquisition and release of the lock belongs inside gbaudio_remove_controls(), not in its caller.
If you disagree, can you please explain why?
Otherwise, will you please submit version two, taking the lock inside gbaudio_remove_controls()?
Thanks.
-Alex
> Fixes: 510e340efe0c ("staging: greybus: audio: Add helper APIs for dynamic audio modules") > Signed-off-by: Takashi Iwai <tiwai@suse.de> > --- > drivers/staging/greybus/audio_helper.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/drivers/staging/greybus/audio_helper.c b/drivers/staging/greybus/audio_helper.c > index 1ed4772d2771..843760675876 100644 > --- a/drivers/staging/greybus/audio_helper.c > +++ b/drivers/staging/greybus/audio_helper.c > @@ -192,7 +192,11 @@ int gbaudio_remove_component_controls(struct snd_soc_component *component, > unsigned int num_controls) > { > struct snd_card *card = component->card->snd_card; > + int err; > > - return gbaudio_remove_controls(card, component->dev, controls, > - num_controls, component->name_prefix); > + down_write(&card->controls_rwsem); > + err = gbaudio_remove_controls(card, component->dev, controls, > + num_controls, component->name_prefix); > + up_write(&card->controls_rwsem); > + return err; > } >
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