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Commit 641b4879 authored by Takashi Iwai's avatar Takashi Iwai
Browse files

ALSA: usb-audio - Cache mixer values 



Cache mixer values in usb-audio driver to reduce too excessive
accesses to the hardware.

Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 37a76bd4

sound/usb/usbmixer.c

+70 −52
Original line number Diff line number Diff line
@@ -110,6 +110,8 @@ struct mixer_build { 
	const struct usbmix_selector_map *selector_map;

};



#define MAX_CHANNELS	10	/* max logical channels */



struct usb_mixer_elem_info {

	struct usb_mixer_interface *mixer;

	struct usb_mixer_elem_info *next_id_elem; /* list of controls with same id */
@@ -120,6 +122,8 @@ struct usb_mixer_elem_info { 
	int channels;

	int val_type;

	int min, max, res;

	int cached;

	int cache_val[MAX_CHANNELS];

	u8 initialized;

};
@@ -181,8 +185,6 @@ enum { 
	USB_PROC_DCR_RELEASE = 6,

};



#define MAX_CHANNELS	10	/* max logical channels */





/*

 * manual mapping of mixer names
@@ -376,11 +378,35 @@ static int get_cur_ctl_value(struct usb_mixer_elem_info *cval, int validx, int * 
}



/* channel = 0: master, 1 = first channel */

static inline int get_cur_mix_value(struct usb_mixer_elem_info *cval, int channel, int *value)

static inline int get_cur_mix_raw(struct usb_mixer_elem_info *cval,

				  int channel, int *value)

{

	return get_ctl_value(cval, GET_CUR, (cval->control << 8) | channel, value);

}



static int get_cur_mix_value(struct usb_mixer_elem_info *cval,

			     int channel, int index, int *value)

{

	int err;



	if (cval->cached & (1 << channel)) {

		*value = cval->cache_val[index];

		return 0;

	}

	err = get_cur_mix_raw(cval, channel, value);

	if (err < 0) {

		if (!cval->mixer->ignore_ctl_error)

			snd_printd(KERN_ERR "cannot get current value for "

				   "control %d ch %d: err = %d\n",

				   cval->control, channel, err);

		return err;

	}

	cval->cached |= 1 << channel;

	cval->cache_val[index] = *value;

	return 0;

}





/*

 * set a mixer value

 */
@@ -412,9 +438,17 @@ static int set_cur_ctl_value(struct usb_mixer_elem_info *cval, int validx, int v 
	return set_ctl_value(cval, SET_CUR, validx, value);

}



static inline int set_cur_mix_value(struct usb_mixer_elem_info *cval, int channel, int value)

static int set_cur_mix_value(struct usb_mixer_elem_info *cval, int channel,

			     int index, int value)

{

	return set_ctl_value(cval, SET_CUR, (cval->control << 8) | channel, value);

	int err;

	err = set_ctl_value(cval, SET_CUR, (cval->control << 8) | channel,

			    value);

	if (err < 0)

		return err;

	cval->cached |= 1 << channel;

	cval->cache_val[index] = value;

	return 0;

}



/*
@@ -718,7 +752,7 @@ static int get_min_max(struct usb_mixer_elem_info *cval, int default_min) 
		if (cval->min + cval->res < cval->max) {

			int last_valid_res = cval->res;

			int saved, test, check;

			get_cur_mix_value(cval, minchn, &saved);

			get_cur_mix_raw(cval, minchn, &saved);

			for (;;) {

				test = saved;

				if (test < cval->max)
@@ -726,8 +760,8 @@ static int get_min_max(struct usb_mixer_elem_info *cval, int default_min) 
				else

					test -= cval->res;

				if (test < cval->min || test > cval->max ||

				    set_cur_mix_value(cval, minchn, test) ||

				    get_cur_mix_value(cval, minchn, &check)) {

				    set_cur_mix_value(cval, minchn, 0, test) ||

				    get_cur_mix_raw(cval, minchn, &check)) {

					cval->res = last_valid_res;

					break;

				}
@@ -735,7 +769,7 @@ static int get_min_max(struct usb_mixer_elem_info *cval, int default_min) 
					break;

				cval->res *= 2;

			}

			set_cur_mix_value(cval, minchn, saved);

			set_cur_mix_value(cval, minchn, 0, saved);

		}



		cval->initialized = 1;
@@ -775,35 +809,25 @@ static int mixer_ctl_feature_get(struct snd_kcontrol *kcontrol, struct snd_ctl_e 
	struct usb_mixer_elem_info *cval = kcontrol->private_data;

	int c, cnt, val, err;



	ucontrol->value.integer.value[0] = cval->min;

	if (cval->cmask) {

		cnt = 0;

		for (c = 0; c < MAX_CHANNELS; c++) {

			if (cval->cmask & (1 << c)) {

				err = get_cur_mix_value(cval, c + 1, &val);

				if (err < 0) {

					if (cval->mixer->ignore_ctl_error) {

						ucontrol->value.integer.value[0] = cval->min;

						return 0;

					}

					snd_printd(KERN_ERR "cannot get current value for control %d ch %d: err = %d\n", cval->control, c + 1, err);

					return err;

				}

			if (!(cval->cmask & (1 << c)))

				continue;

			err = get_cur_mix_value(cval, c + 1, cnt, &val);

			if (err < 0)

				return cval->mixer->ignore_ctl_error ? 0 : err;

			val = get_relative_value(cval, val);

			ucontrol->value.integer.value[cnt] = val;

			cnt++;

		}

		}

		return 0;

	} else {

		/* master channel */

		err = get_cur_mix_value(cval, 0, &val);

		if (err < 0) {

			if (cval->mixer->ignore_ctl_error) {

				ucontrol->value.integer.value[0] = cval->min;

				return 0;

			}

			snd_printd(KERN_ERR "cannot get current value for control %d master ch: err = %d\n", cval->control, err);

			return err;

		}

		err = get_cur_mix_value(cval, 0, 0, &val);

		if (err < 0)

			return cval->mixer->ignore_ctl_error ? 0 : err;

		val = get_relative_value(cval, val);

		ucontrol->value.integer.value[0] = val;

	}
@@ -820,34 +844,28 @@ static int mixer_ctl_feature_put(struct snd_kcontrol *kcontrol, struct snd_ctl_e 
	if (cval->cmask) {

		cnt = 0;

		for (c = 0; c < MAX_CHANNELS; c++) {

			if (cval->cmask & (1 << c)) {

				err = get_cur_mix_value(cval, c + 1, &oval);

				if (err < 0) {

					if (cval->mixer->ignore_ctl_error)

						return 0;

					return err;

				}

			if (!(cval->cmask & (1 << c)))

				continue;

			err = get_cur_mix_value(cval, c + 1, cnt, &oval);

			if (err < 0)

				return cval->mixer->ignore_ctl_error ? 0 : err;

			val = ucontrol->value.integer.value[cnt];

			val = get_abs_value(cval, val);

			if (oval != val) {

					set_cur_mix_value(cval, c + 1, val);

				set_cur_mix_value(cval, c + 1, cnt, val);

				changed = 1;

			}

				get_cur_mix_value(cval, c + 1, &val);

			cnt++;

		}

		}

	} else {

		/* master channel */

		err = get_cur_mix_value(cval, 0, &oval);

		if (err < 0 && cval->mixer->ignore_ctl_error)

			return 0;

		err = get_cur_mix_value(cval, 0, 0, &oval);

		if (err < 0)

			return err;

			return cval->mixer->ignore_ctl_error ? 0 : err;

		val = ucontrol->value.integer.value[0];

		val = get_abs_value(cval, val);

		if (val != oval) {

			set_cur_mix_value(cval, 0, val);

			set_cur_mix_value(cval, 0, 0, val);

			changed = 1;

		}

	}