* [PATCH] sound: rcar: use fast_io for bus
@ 2014-03-27 22:55 Ben Dooks
0 siblings, 0 replies; only message in thread
From: Ben Dooks @ 2014-03-27 22:55 UTC (permalink / raw)
To: alsa-devel
Cc: kuninori.morimoto.gx, broonie, lgirdwood, linux-sh, magnus.damm,
Ben Dooks
The rcar sound driver uses regmap to access registers in various parts
of the block and uses regmap to manage mappings. The regmap is created
without fast_io set, which means it locks with a mutex rather than a
lighter-spinlock.
The use of the mutex lock causes issues when the IRQ handler is entered
as the code needs to read/write register values and thus with lock
debugging enabled the system outputs a number of warnings such as:
BUG: sleeping function called from invalid context at rnel/locking/mutex.c:616
The rcar registers are all connected via APB bus and thus not that slow
to access. The fix is to set the fast_io in the code so that regmap creates
the regmap structures using the faster spinlock functions.
Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
---
sound/soc/sh/rcar/gen.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/sound/soc/sh/rcar/gen.c b/sound/soc/sh/rcar/gen.c
index 9094970..6468962 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,
--
1.9.0
^ permalink raw reply related [flat|nested] only message in thread
only message in thread, other threads:[~2014-03-27 22:55 UTC | newest]
Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2014-03-27 22:55 [PATCH] sound: rcar: use fast_io for bus Ben Dooks
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).