ASoC: remove io_mutex (8538a119) · Commits · 戴 / test

Remove the io_mutex. It has a drawback of serializing all accesses to snd_soc_update_bits() even when multiple codecs are in use. In addition, it fails to actually do its task - during snd_soc_update_bits(), dapm_update_bits() may also be accessing the same register which may result in an outdated register value. Signed-off-by:

Eero Nurkkala <ext-eero.nurkkala@nokia.com> Signed-off-by:

Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/soc-core.c

+0 −5

Original line number	Diff line number	Diff line
		@@ -37,7 +37,6 @@
		#include <sound/initval.h>

		static DEFINE_MUTEX(pcm_mutex);
		static DEFINE_MUTEX(io_mutex);
		static DECLARE_WAIT_QUEUE_HEAD(soc_pm_waitq);

		#ifdef CONFIG_DEBUG_FS
		@@ -1346,14 +1345,12 @@ int snd_soc_update_bits(struct snd_soc_codec *codec, unsigned short reg,
		int change;
		unsigned int old, new;

		mutex_lock(&io_mutex);
		old = snd_soc_read(codec, reg);
		new = (old & ~mask) \| value;
		change = old != new;
		if (change)
		snd_soc_write(codec, reg, new);

		mutex_unlock(&io_mutex);
		return change;
		}
		EXPORT_SYMBOL_GPL(snd_soc_update_bits);
		@@ -1376,11 +1373,9 @@ int snd_soc_test_bits(struct snd_soc_codec *codec, unsigned short reg,
		int change;
		unsigned int old, new;

		mutex_lock(&io_mutex);
		old = snd_soc_read(codec, reg);
		new = (old & ~mask) \| value;
		change = old != new;
		mutex_unlock(&io_mutex);

		return change;
		}

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