ASoC: don't register AC97 devices twice (0562f788) · Commits · 戴 / test

With generic AC97 ASoC glue driver (codec/ac97.c), we get following warning when the device is registered (slightly stripped the backtrace): kobject (c5a863e8): tried to init an initialized object, something is seriously wrong. [<c00254fc>] (unwind_backtrace+0x0/0xec) [<c014fad0>] (kobject_init+0x38/0x70) [<c0171e94>] (device_initialize+0x20/0x70) [<c017267c>] (device_register+0xc/0x18) [<bf20db70>] (snd_soc_instantiate_cards+0x924/0xacc [snd_soc_core]) [<bf20e0d0>] (snd_soc_register_platform+0x16c/0x198 [snd_soc_core]) [<c0175304>] (platform_drv_probe+0x18/0x1c) [<c0174454>] (driver_probe_device+0xb0/0x16c) [<c017456c>] (__driver_attach+0x5c/0x7c) [<c0173cec>] (bus_for_each_dev+0x48/0x78) [<c0173600>] (bus_add_driver+0x98/0x214) [<c0174834>] (driver_register+0xa4/0x130) [<c001f410>] (do_one_initcall+0xd0/0x1a4) [<c0062ddc>] (sys_init_module+0x12b0/0x1454) This happens because the generic AC97 glue driver creates its codec->ac97 via calling snd_ac97_mixer(). snd_ac97_mixer() provides own version of snd_device.register which handles the device registration when snd_card_register() is called. To avoid registering the AC97 device twice, we add a new flag to the snd_soc_codec: ac97_created which tells whether the AC97 device was created by SoC subsystem. Signed-off-by:

Mika Westerberg <mika.westerberg@iki.fi> Acked-by:

Liam Girdwood <lrg@slimlogic.co.uk> Signed-off-by:

Mark Brown <broonie@opensource.wolfsonmicro.com>

include/sound/soc.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -442,6 +442,7 @@ struct snd_soc_codec {
		unsigned int suspended:1; /* Codec is in suspend PM state */
		unsigned int probed:1; /* Codec has been probed */
		unsigned int ac97_registered:1; /* Codec has been AC97 registered */
		unsigned int ac97_created:1; /* Codec has been created by SoC */
		unsigned int sysfs_registered:1; /* codec has been sysfs registered */

		/* codec IO */

sound/soc/soc-core.c

+18 −0

Original line number	Diff line number	Diff line
		@@ -1497,6 +1497,16 @@ static int soc_register_ac97_dai_link(struct snd_soc_pcm_runtime *rtd)
		* for the generic AC97 subsystem.
		*/
		if (rtd->codec_dai->driver->ac97_control && !rtd->codec->ac97_registered) {
		/*
		* It is possible that the AC97 device is already registered to
		* the device subsystem. This happens when the device is created
		* via snd_ac97_mixer(). Currently only SoC codec that does so
		* is the generic AC97 glue but others migh emerge.
		*
		* In those cases we don't try to register the device again.
		*/
		if (!rtd->codec->ac97_created)
		return 0;

		ret = soc_ac97_dev_register(rtd->codec);
		if (ret < 0) {
		@@ -1812,6 +1822,13 @@ int snd_soc_new_ac97_codec(struct snd_soc_codec *codec,

		codec->ac97->bus->ops = ops;
		codec->ac97->num = num;

		/*
		* Mark the AC97 device to be created by us. This way we ensure that the
		* device will be registered with the device subsystem later on.
		*/
		codec->ac97_created = 1;

		mutex_unlock(&codec->mutex);
		return 0;
		}
		@@ -1832,6 +1849,7 @@ void snd_soc_free_ac97_codec(struct snd_soc_codec *codec)
		kfree(codec->ac97->bus);
		kfree(codec->ac97);
		codec->ac97 = NULL;
		codec->ac97_created = 0;
		mutex_unlock(&codec->mutex);
		}
		EXPORT_SYMBOL_GPL(snd_soc_free_ac97_codec);

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