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Commit a1682a64 authored by Meng Wang's avatar Meng Wang Committed by Meng Wang
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ALSA: PCM: volume API implementation 



Introduced a new helper function snd_pcm_add_volume_ctls() to
create control elements representing the volume for each PCM
(sub)stream.

This patch also squashes the logic implemented by below change-

ASoC: Fix freed memory access of pcm stream kctl

Consider sound card instantiate fails due to
audrx init failure. In such case, all dais/ctls
are de-registered and freed. But as part of it,
access to unregistered ctls for pcm_chmap and similar
controls result in crash.  Ctls are freed at disconnection
but the disconnect is called only when it was registered.

CRs-Fixed: 1038054
Change-Id: Ief8817b4ec000c058d46aa021977b7c6003c0011
Signed-off-by: default avatarLaxminath Kasam <lkasam@codeaurora.org>
Signed-off-by: default avatarDamir Didjusto <damird@codeaurora.org>
Signed-off-by: default avatarBanajit Goswami <bgoswami@codeaurora.org>
Signed-off-by: default avatarSudheer Papothi <spapothi@codeaurora.org>
Signed-off-by: default avatarMeng Wang <mwang@codeaurora.org>
parent a70116e1

include/sound/pcm.h

+29 −0
Original line number Diff line number Diff line
@@ -501,6 +501,9 @@ struct snd_pcm_str { 
#endif

#endif

	struct snd_kcontrol *chmap_kctl; /* channel-mapping controls */

#ifdef CONFIG_AUDIO_QGKI

	struct snd_kcontrol *vol_kctl; /* volume controls */

#endif

	struct device dev;

};
@@ -1417,6 +1420,32 @@ static inline u64 pcm_format_to_bits(snd_pcm_format_t pcm_format) 
	return 1ULL << (__force int) pcm_format;

}



#ifdef CONFIG_AUDIO_QGKI

/*

 * PCM Volume control API

 */

/* array element of volume */

struct snd_pcm_volume_elem {

	int volume;

};



/* pp information; retrieved via snd_kcontrol_chip() */

struct snd_pcm_volume {

	struct snd_pcm *pcm;	/* assigned PCM instance */

	int stream;		/* PLAYBACK or CAPTURE */

	struct snd_kcontrol *kctl;

	const struct snd_pcm_volume_elem *volume;

	int max_length;

	void *private_data;	/* optional: private data pointer */

};



int snd_pcm_add_volume_ctls(struct snd_pcm *pcm, int stream,

			   const struct snd_pcm_volume_elem *volume,

			   int max_length,

			   unsigned long private_value,

			   struct snd_pcm_volume **info_ret);

#endif



/* printk helpers */

#define pcm_err(pcm, fmt, args...) \

	dev_err((pcm)->card->dev, fmt, ##args)

sound/core/pcm.c

+6 −0
Original line number Diff line number Diff line
@@ -816,6 +816,12 @@ static void free_chmap(struct snd_pcm_str *pstr) 
		snd_ctl_remove(pstr->pcm->card, pstr->chmap_kctl);

		pstr->chmap_kctl = NULL;

	}

#ifdef CONFIG_AUDIO_QGKI

	if (pstr->vol_kctl) {

		snd_ctl_remove(pstr->pcm->card, pstr->vol_kctl);

		pstr->vol_kctl = NULL;

	}

#endif

}



static void snd_pcm_free_stream(struct snd_pcm_str * pstr)

sound/core/pcm_lib.c

+97 −0
Original line number Diff line number Diff line
@@ -30,6 +30,10 @@ 
#define trace_applptr(substream, prev, curr)

#endif



#ifdef CONFIG_AUDIO_QGKI

#define STRING_LENGTH_OF_INT 12

#endif



static int fill_silence_frames(struct snd_pcm_substream *substream,

			       snd_pcm_uframes_t off, snd_pcm_uframes_t frames);
@@ -2400,6 +2404,26 @@ static void pcm_chmap_ctl_private_free(struct snd_kcontrol *kcontrol) 
	kfree(info);

}



#ifdef CONFIG_AUDIO_QGKI

static int pcm_volume_ctl_info(struct snd_kcontrol *kcontrol,

				struct snd_ctl_elem_info *uinfo)

{

	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;

	uinfo->count = 1;

	uinfo->value.integer.min = 0;

	uinfo->value.integer.max = 0x2000;

	return 0;

}



static void pcm_volume_ctl_private_free(struct snd_kcontrol *kcontrol)

{

	struct snd_pcm_volume *info = snd_kcontrol_chip(kcontrol);



	info->pcm->streams[info->stream].vol_kctl = NULL;

	kfree(info);

}

#endif



/**

 * snd_pcm_add_chmap_ctls - create channel-mapping control elements

 * @pcm: the assigned PCM instance
@@ -2461,3 +2485,76 @@ int snd_pcm_add_chmap_ctls(struct snd_pcm *pcm, int stream, 
	return 0;

}

EXPORT_SYMBOL_GPL(snd_pcm_add_chmap_ctls);



#ifdef CONFIG_AUDIO_QGKI

/**

 * snd_pcm_add_volume_ctls - create volume control elements

 * @pcm: the assigned PCM instance

 * @stream: stream direction

 * @max_length: the max length of the volume parameter of stream

 * @private_value: the value passed to each kcontrol's private_value field

 * @info_ret: store struct snd_pcm_volume instance if non-NULL

 *

 * Create volume control elements assigned to the given PCM stream(s).

 * Returns zero if succeed, or a negative error value.

 */

int snd_pcm_add_volume_ctls(struct snd_pcm *pcm, int stream,

			   const struct snd_pcm_volume_elem *volume,

			   int max_length,

			   unsigned long private_value,

			   struct snd_pcm_volume **info_ret)

{

	struct snd_pcm_volume *info;

	struct snd_kcontrol_new knew = {

		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,

		.access = SNDRV_CTL_ELEM_ACCESS_TLV_READ |

			SNDRV_CTL_ELEM_ACCESS_READWRITE,

		.info = pcm_volume_ctl_info,

	};

	int err;

	int size;



	info = kzalloc(sizeof(*info), GFP_KERNEL);

	if (!info)

		return -ENOMEM;

	info->pcm = pcm;

	info->stream = stream;

	info->volume = volume;

	info->max_length = max_length;

	size = sizeof("Playback ") + sizeof(" Volume") +

		STRING_LENGTH_OF_INT*sizeof(char) + 1;

	knew.name = kzalloc(size, GFP_KERNEL);

	if (!knew.name) {

		kfree(info);

		return -ENOMEM;

	}

	if (stream == SNDRV_PCM_STREAM_PLAYBACK)

		snprintf((char *)knew.name, size, "%s %d %s",

			"Playback", pcm->device, "Volume");

	else

		snprintf((char *)knew.name, size, "%s %d %s",

			"Capture", pcm->device, "Volume");

	knew.device = pcm->device;

	knew.count = pcm->streams[stream].substream_count;

	knew.private_value = private_value;

	info->kctl = snd_ctl_new1(&knew, info);

	if (!info->kctl) {

		kfree(info);

		kfree(knew.name);

		return -ENOMEM;

	}

	info->kctl->private_free = pcm_volume_ctl_private_free;

	err = snd_ctl_add(pcm->card, info->kctl);

	if (err < 0) {

		kfree(info);

		kfree(knew.name);

		return -ENOMEM;

	}

	pcm->streams[stream].vol_kctl = info->kctl;

	if (info_ret)

		*info_ret = info;

	kfree(knew.name);

	return 0;

}

EXPORT_SYMBOL(snd_pcm_add_volume_ctls);

#endif