Messages in this thread | | | From | Arnaud POULIQUEN <> | Subject | RE: [PATCH] ASoC: sti: sti_uniperif: Remove driver | Date | Tue, 15 Mar 2022 15:27:40 +0000 |
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ST Restricted
> -----Original Message----- > From: Takashi Iwai <tiwai@suse.de> > Sent: mardi 15 mars 2022 15:35 > To: Arnaud POULIQUEN <arnaud.pouliquen@st.com> > Cc: Daniel Palmer <daniel@0x0f.com>; broonie@kernel.org; tiwai@suse.com; > alsa-devel@alsa-project.org; linux-kernel@vger.kernel.org > Subject: Re: [PATCH] ASoC: sti: sti_uniperif: Remove driver > > On Tue, 15 Mar 2022 14:15:20 +0100, > Arnaud POULIQUEN wrote: > > > > Hello, > > > > > > ST Restricted > > > > > -----Original Message----- > > > From: Takashi Iwai <tiwai@suse.de> > > > Sent: mardi 15 mars 2022 11:28 > > > To: Daniel Palmer <daniel@0x0f.com> > > > Cc: broonie@kernel.org; tiwai@suse.com; Arnaud POULIQUEN > > > <arnaud.pouliquen@st.com>; alsa-devel@alsa-project.org; linux- > > > kernel@vger.kernel.org > > > Subject: Re: [PATCH] ASoC: sti: sti_uniperif: Remove driver > > > > > > On Tue, 15 Mar 2022 10:13:19 +0100, > > > Daniel Palmer wrote: > > > > > > > > This driver seems to be in the "only good for attracting bot > > > > generated patches" phase of it's life. > > > > > > > > It doesn't seem like anyone actually tested the patches that have > > > > been applied in the last few years as uni_reader_irq_handler() had > > > > a dead lock added to it (it locks the stream, then calls > > > > snd_pcm_stop_xrun() which will also lock the stream). > > > > > > Mea culpa, that was an obvious deadlock I overlooked in the patch > > > series. > > > > > > > Seems best just to remove it. > > > > > > > > Signed-off-by: Daniel Palmer <daniel@0x0f.com> > > > > --- > > > > I've never used this driver, don't have the hardware etc. > > > > I just noticed that this looks broken when debugging my own > > > > driver that uses snd_pcm_stop_xrun() and was looking at other > > > > users to see if I was using it wrong and noticed this was the > > > > only place that locked the stream before calling > > > > snd_pcm_stop_xrun(). > > > > > > > > There are probably some other bits of the driver that should be > > > > removed but I didn't look that hard. > > > > > > > > TL;DR; This driver seems broken, seems like nobody uses it. > > > > Maybe it should be deleted? > > > > > > Yeah, that looks dead. > > > > > > > The platform is still used for instance: > > https://lore.kernel.org/all/1d95209f-9cb4-47a3-2696-7a93df7cdc05@foss. > > st.com/ > > > > So please do not remove the driver > > Ah, it's always good to see a vital sign! > > > The issue has not been detected because it is related to an error that > > occurs only when we reach the limit of the platform, with application > > that stop the stream at same time. > > So almost no chance to occur. > > > > > OTOH, if anyone really wants to keep the stuff, please revert the > > > commit dc865fb9e7c2251c9585ff6a7bf185d499db13e4. > > > > Yes reverting the commit is one solution. > > The other is to clean-up the snd_pcm_stream_lock/ > > snd_pcm_stream_unlock in the Handler. > > That would work, but maybe it's safer to keep that lock, as the state change > isn't protected by irq_lock but only implicitly by stream lock in start/stop > callbacks.
You are right, trying to use the snd_pcm_stop_xrun needs deeper update that could introduce regression. It seems wiser to revert your commit dc865fb9e7c2 as you propose.
Thanks, Arnaud
> > > thanks, > > Takashi
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