commit 5b30b062ee1cd00e0e5823087a2baeee8ebcce21
author andysu <andysu@android.com> Fri Apr 20 16:34:06 2018 +0800
committer Eric Laurent <elaurent@google.com> Wed Apr 25 18:42:59 2018 -0700
tree 141a77f44830738e4fd16fe9ff774331ac871009
parent 9c021b9497ed602257c54549ff5f796e2afae2d0

hal: prevent device switch when speaker swap channel

Issue happens while music playback with touch sound enabled.
music playback started in the first place and touch sound created
low-latency playback with device switch when device orientation
changed.
This fix disabled the device switch when acdb tuning is the same
for SPEAKER & SPEAKER_REVERSE. Since walleye uses ADSP mixer control
for swap channel, the acdb setting is the same for SPEAKER &
SPEAKER_REVERSE.
Test: self-tested for over 50 times.
Bug: 77499491

Change-Id: Ie602cf1b1ee533a46714c569fa0da9b40da9e25b
Signed-off-by: andysu <andysu@android.com>

hal/msm8916/platform.c

diff --git a/hal/msm8916/platform.c b/hal/msm8916/platform.c
index 4b91bcd..1f8da65 100644
--- a/hal/msm8916/platform.c
+++ b/hal/msm8916/platform.c
@@ -1701,7 +1701,13 @@
     } else if (devices & AUDIO_DEVICE_OUT_LINE) {
         snd_device = SND_DEVICE_OUT_LINE;
     } else if (devices & AUDIO_DEVICE_OUT_SPEAKER) {
-        if (my_data->speaker_lr_swap)
+        /*
+         * Perform device switch only if acdb tuning is different between SPEAKER & SPEAKER_REVERSE,
+         * Or there will be a small pause while performing device switch.
+         */
+        if (my_data->speaker_lr_swap &&
+            (acdb_device_table[SND_DEVICE_OUT_SPEAKER] !=
+            acdb_device_table[SND_DEVICE_OUT_SPEAKER_REVERSE]))
             snd_device = SND_DEVICE_OUT_SPEAKER_REVERSE;
         else
             snd_device = SND_DEVICE_OUT_SPEAKER;