From: Kuninori Morimoto <kuninori.morimoto.gx@gmail.com>
To: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Cc: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>,
alsa-devel@alsa-project.org, linux-sh@vger.kernel.org
Subject: Re: [alsa-devel] [PATCH] ASoC: rsnd: Protect register accesses with a spinlock instead of a mutex
Date: Thu, 24 Jul 2014 02:16:34 +0000 [thread overview]
Message-ID: <87tx67a4cf.wl%kuninori.morimoto.gx@gmail.com> (raw)
In-Reply-To: <87y4vja9xq.wl%kuninori.morimoto.gx@renesas.com>
Hi Laurent
> > The hardware registers are accessed from atomic contexts (the
> > rsnd_soc_dai_trigger function, for instance, is called with the PCM
> > substream spinlock held). They thus can't be protected by a mutex.
> >
> > Protect regmap register accesses with a spinlock instead of a mutex by
> > setting the fast_io flag.
> >
> > Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> > ---
> > sound/soc/sh/rcar/gen.c | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > An even better solution might be to use regmap-mmio instead of a custom bus.
> > Morimoto-san, is there anything that would prevent the driver from switching
> > to regmap-mmio ?
>
> I guess it is possilbe to use regmap-mmio.
> I check it.
Hmm... rsnd driver is using "regmap_field".
regmap-mmio requests "offset" on "reg"
regmap-filed requests "address" on "reg"
So, if rsnd driver uses regmap-mmio,
then, it needs tricky initialize like...
regmap_init_mmio(dev, 0, config)
Best regards
---
Kuninori Morimoto
WARNING: multiple messages have this Message-ID (diff)
From: Kuninori Morimoto <kuninori.morimoto.gx@gmail.com>
To: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Cc: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>,
alsa-devel@alsa-project.org, linux-sh@vger.kernel.org
Subject: Re: [alsa-devel] [PATCH] ASoC: rsnd: Protect register accesses with a spinlock instead of a mutex
Date: Wed, 23 Jul 2014 19:16:34 -0700 (PDT) [thread overview]
Message-ID: <87tx67a4cf.wl%kuninori.morimoto.gx@gmail.com> (raw)
In-Reply-To: <87y4vja9xq.wl%kuninori.morimoto.gx@renesas.com>
Hi Laurent
> > The hardware registers are accessed from atomic contexts (the
> > rsnd_soc_dai_trigger function, for instance, is called with the PCM
> > substream spinlock held). They thus can't be protected by a mutex.
> >
> > Protect regmap register accesses with a spinlock instead of a mutex by
> > setting the fast_io flag.
> >
> > Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> > ---
> > sound/soc/sh/rcar/gen.c | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > An even better solution might be to use regmap-mmio instead of a custom bus.
> > Morimoto-san, is there anything that would prevent the driver from switching
> > to regmap-mmio ?
>
> I guess it is possilbe to use regmap-mmio.
> I check it.
Hmm... rsnd driver is using "regmap_field".
regmap-mmio requests "offset" on "reg"
regmap-filed requests "address" on "reg"
So, if rsnd driver uses regmap-mmio,
then, it needs tricky initialize like...
regmap_init_mmio(dev, 0, config)
Best regards
---
Kuninori Morimoto
next prev parent reply other threads:[~2014-07-24 2:16 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-23 21:19 [PATCH] ASoC: rsnd: Protect register accesses with a spinlock instead of a mutex Laurent Pinchart
2014-07-23 21:19 ` Laurent Pinchart
2014-07-24 0:15 ` [alsa-devel] " Kuninori Morimoto
2014-07-24 0:15 ` Kuninori Morimoto
2014-07-24 2:16 ` Kuninori Morimoto [this message]
2014-07-24 2:16 ` Kuninori Morimoto
2014-07-28 5:59 ` Lars-Peter Clausen
2014-07-28 5:59 ` Lars-Peter Clausen
2014-07-28 7:40 ` Kuninori Morimoto
2014-07-28 7:40 ` Kuninori Morimoto
2014-07-28 8:03 ` Lars-Peter Clausen
2014-07-28 8:03 ` Lars-Peter Clausen
2014-07-28 8:33 ` Kuninori Morimoto
2014-07-28 8:33 ` Kuninori Morimoto
2014-07-27 10:36 ` Ben Dooks
2014-07-27 10:36 ` Ben Dooks
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