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From: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
To: alsa-devel@alsa-project.org
Cc: linux-sh@vger.kernel.org,
	Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Subject: [PATCH] ASoC: rsnd: Protect register accesses with a spinlock instead of a mutex
Date: Wed, 23 Jul 2014 21:19:26 +0000	[thread overview]
Message-ID: <1406150366-10169-1-git-send-email-laurent.pinchart+renesas@ideasonboard.com> (raw)

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 ?

diff --git a/sound/soc/sh/rcar/gen.c b/sound/soc/sh/rcar/gen.c
index 73ce4c9..ec9ac5e 100644
--- a/sound/soc/sh/rcar/gen.c
+++ b/sound/soc/sh/rcar/gen.c
@@ -66,6 +66,7 @@ static int rsnd_regmap_read32(void *context,
 }
 
 static struct regmap_bus rsnd_regmap_bus = {
+	.fast_io			= true,
 	.write				= rsnd_regmap_write32,
 	.read				= rsnd_regmap_read32,
 	.reg_format_endian_default	= REGMAP_ENDIAN_NATIVE,
-- 
Regards,

Laurent Pinchart


WARNING: multiple messages have this Message-ID (diff)
From: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
To: alsa-devel@alsa-project.org
Cc: linux-sh@vger.kernel.org,
	Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Subject: [PATCH] ASoC: rsnd: Protect register accesses with a spinlock instead of a mutex
Date: Wed, 23 Jul 2014 23:19:26 +0200	[thread overview]
Message-ID: <1406150366-10169-1-git-send-email-laurent.pinchart+renesas@ideasonboard.com> (raw)

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 ?

diff --git a/sound/soc/sh/rcar/gen.c b/sound/soc/sh/rcar/gen.c
index 73ce4c9..ec9ac5e 100644
--- a/sound/soc/sh/rcar/gen.c
+++ b/sound/soc/sh/rcar/gen.c
@@ -66,6 +66,7 @@ static int rsnd_regmap_read32(void *context,
 }
 
 static struct regmap_bus rsnd_regmap_bus = {
+	.fast_io			= true,
 	.write				= rsnd_regmap_write32,
 	.read				= rsnd_regmap_read32,
 	.reg_format_endian_default	= REGMAP_ENDIAN_NATIVE,
-- 
Regards,

Laurent Pinchart


             reply	other threads:[~2014-07-23 21:19 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-07-23 21:19 Laurent Pinchart [this message]
2014-07-23 21:19 ` [PATCH] ASoC: rsnd: Protect register accesses with a spinlock instead of a mutex 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
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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