Re: [PATCH] ASoC: soc-pcm: Fix and cleanup DPCM locking

[Yixuan Jiang]

Greg KH <greg@xxxxxxxxx> 於 2023年5月6日 週六 下午1:56寫道：
>
> On Thu, May 04, 2023 at 05:21:42PM +0800, yixuanjiang wrote:
> > From: Takashi Iwai <tiwai@xxxxxxx>
> >
> > The existing locking for DPCM has several issues
> > a) a confusing mix of card->mutex and card->pcm_mutex.
> > b) a dpcm_lock spinlock added inconsistently and on paths that could
> > be recursively taken. The use of irqsave/irqrestore was also overkill.
> >
> > The suggested model is:
> >
> > 1) The pcm_mutex is the top-most protection of BE links in the FE. The
> > pcm_mutex is applied always on either the top PCM callbacks or the
> > external call from DAPM, not taken in the internal functions.
> >
> > 2) the FE stream lock is taken in higher levels before invoking
> > dpcm_be_dai_trigger()
> >
> > 3) when adding and deleting a BE, both the pcm_mutex and FE stream
> > lock are taken.
> >
> > Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
> > [clarification of commit message by plbossart]
> > Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
> > Reviewed-by: Kai Vehmanen <kai.vehmanen@xxxxxxxxxxxxxxx>
> > Reviewed-by: Bard Liao <yung-chuan.liao@xxxxxxxxxxxxxxx>
> > Reviewed-by: Ranjani Sridharan <ranjani.sridharan@xxxxxxxxxxxxxxx>
> > Link: https://lore.kernel.org/r/20211207173745.15850-4-pierre-louis.bossart@xxxxxxxxxxxxxxx
> > Cc: stable@xxxxxxxxxxxxxxx # 5.15.x
> > Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
> > ---
>
> What is the git commit id of this patch in Linus's tree?
>
> thanks,
>
> greg k-h

Hi Greg,
For this patch I think it is [3/6] b7898396f4bbe160f546d0c5e9fa17cca9a7d153

>From https://lore.kernel.org/all/163953384515.1515253.13641477106348913835.b4-ty@xxxxxxxxxx/
Seems there are total 6 patches.

[1/6] ASoC: soc-pcm: use GFP_ATOMIC for dpcm structure
      commit: d8a9c6e1f6766a16cf02b4e99a629f3c5512c183
[2/6] ASoC: soc-pcm: align BE 'atomicity' with that of the FE
      commit: bbf7d3b1c4f40eb02dd1dffb500ba00b0bff0303
[3/6] ASoC: soc-pcm: Fix and cleanup DPCM locking
      commit: b7898396f4bbe160f546d0c5e9fa17cca9a7d153
[4/6] ASoC: soc-pcm: serialize BE triggers
      commit: b2ae80663008a7662febe7d13f14ea1b2eb0cd51
[5/6] ASoC: soc-pcm: test refcount before triggering
      commit: 848aedfdc6ba25ad5652797db9266007773e44dd
[6/6] ASoC: soc-pcm: fix BE handling of PAUSE_RELEASE
      commit: 3aa1e96a2b95e2ece198f8dd01e96818971b84df

These 6 patches could directly cherry-pick to in 5.15 without conflict.