ALSA: usb-audio - Cache mixer values
Cache mixer values in usb-audio driver to reduce too excessive
accesses to the hardware.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/usb/usbmixer.c b/sound/usb/usbmixer.c
index 00397c8..c07b3f8 100644
--- a/sound/usb/usbmixer.c
+++ b/sound/usb/usbmixer.c
@@ -110,6 +110,8 @@
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 @@
int channels;
int val_type;
int min, max, res;
+ int cached;
+ int cache_val[MAX_CHANNELS];
u8 initialized;
};
@@ -181,8 +185,6 @@
USB_PROC_DCR_RELEASE = 6,
};
-#define MAX_CHANNELS 10 /* max logical channels */
-
/*
* manual mapping of mixer names
@@ -376,11 +378,35 @@
}
/* 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 @@
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 @@
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 @@
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 @@
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 @@
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;
- }
- val = get_relative_value(cval, val);
- ucontrol->value.integer.value[cnt] = val;
- cnt++;
- }
+ 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 @@
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;
- }
- val = ucontrol->value.integer.value[cnt];
- val = get_abs_value(cval, val);
- if (oval != val) {
- set_cur_mix_value(cval, c + 1, val);
- changed = 1;
- }
- get_cur_mix_value(cval, c + 1, &val);
- cnt++;
+ 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, cnt, val);
+ changed = 1;
}
+ 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;
}
}