Ramp speaker gain when swapping L/R channels for ACDB change
Bug 24096455
Change-Id: If4014621e8e53cee1bbb57b84f10d529ce958048
diff --git a/hal/msm8974/platform.c b/hal/msm8974/platform.c
index 1cc6eac..a753c0f 100644
--- a/hal/msm8974/platform.c
+++ b/hal/msm8974/platform.c
@@ -2404,6 +2404,67 @@
return ret;
}
+#define DEFAULT_NOMINAL_SPEAKER_GAIN 20
+int ramp_speaker_gain(struct audio_device *adev, bool ramp_up, int target_ramp_up_gain) {
+ // backup_gain: gain to try to set in case of an error during ramp
+ int start_gain, end_gain, step, backup_gain, i;
+ bool error = false;
+ const struct mixer_ctl *ctl;
+ const char *mixer_ctl_name_gain_left = "Left Speaker Gain";
+ const char *mixer_ctl_name_gain_right = "Right Speaker Gain";
+ struct mixer_ctl *ctl_left = mixer_get_ctl_by_name(adev->mixer, mixer_ctl_name_gain_left);
+ struct mixer_ctl *ctl_right = mixer_get_ctl_by_name(adev->mixer, mixer_ctl_name_gain_right);
+ if (!ctl_left || !ctl_right) {
+ ALOGE("%s: Could not get ctl for mixer cmd - %s or %s, not applying speaker gain ramp",
+ __func__, mixer_ctl_name_gain_left, mixer_ctl_name_gain_right);
+ return -EINVAL;
+ } else if ((mixer_ctl_get_num_values(ctl_left) != 1)
+ || (mixer_ctl_get_num_values(ctl_right) != 1)) {
+ ALOGE("%s: Unexpected num values for mixer cmd - %s or %s, not applying speaker gain ramp",
+ __func__, mixer_ctl_name_gain_left, mixer_ctl_name_gain_right);
+ return -EINVAL;
+ }
+ if (ramp_up) {
+ start_gain = 0;
+ end_gain = target_ramp_up_gain > 0 ? target_ramp_up_gain : DEFAULT_NOMINAL_SPEAKER_GAIN;
+ step = +1;
+ backup_gain = end_gain;
+ } else {
+ // using same gain on left and right
+ const int left_gain = mixer_ctl_get_value(ctl_left, 0);
+ start_gain = left_gain > 0 ? left_gain : DEFAULT_NOMINAL_SPEAKER_GAIN;
+ end_gain = 0;
+ step = -1;
+ backup_gain = start_gain;
+ }
+ for (i = start_gain ; i != (end_gain + step) ; i += step) {
+ //ALOGV("setting speaker gain to %d", i);
+ if (mixer_ctl_set_value(ctl_left, 0, i)) {
+ ALOGE("%s: error setting %s to %d during gain ramp",
+ __func__, mixer_ctl_name_gain_left, i);
+ error = true;
+ break;
+ }
+ if (mixer_ctl_set_value(ctl_right, 0, i)) {
+ ALOGE("%s: error setting %s to %d during gain ramp",
+ __func__, mixer_ctl_name_gain_right, i);
+ error = true;
+ break;
+ }
+ usleep(1000);
+ }
+ if (error) {
+ // an error occured during the ramp, let's still try to go back to a safe volume
+ if (mixer_ctl_set_value(ctl_left, 0, backup_gain)) {
+ ALOGE("%s: error restoring left gain to %d", __func__, backup_gain);
+ }
+ if (mixer_ctl_set_value(ctl_right, 0, backup_gain)) {
+ ALOGE("%s: error restoring right gain to %d", __func__, backup_gain);
+ }
+ }
+ return start_gain;
+}
+
int platform_swap_lr_channels(struct audio_device *adev, bool swap_channels)
{
// only update if there is active pcm playback on speaker
@@ -2425,7 +2486,11 @@
*/
if (acdb_device_table[SND_DEVICE_OUT_SPEAKER] !=
acdb_device_table[SND_DEVICE_OUT_SPEAKER_REVERSE]) {
+ const int initial_skpr_gain = ramp_speaker_gain(adev, false /*ramp_up*/, -1);
select_devices(adev, usecase->id);
+ if (initial_skpr_gain != -EINVAL) {
+ ramp_speaker_gain(adev, true /*ramp_up*/, initial_skpr_gain);
+ }
} else {
const char *mixer_path;
if (swap_channels) {