hal: bug fixes for PCM offload
When pcm offload is done, override the buffer size
that was calculated and use the value from the system property
Make write call blocking if small buffers are used in offload
Update latency value for pcm offload with small buffer hint based
on period size and period count.
Change-Id: Ic74caa6bd172c8e4554384e9fa98a5137117f07c
diff --git a/hal/msm8974/platform.c b/hal/msm8974/platform.c
index e39c48e..7f54a78 100644
--- a/hal/msm8974/platform.c
+++ b/hal/msm8974/platform.c
@@ -63,6 +63,8 @@
/* Used in calculating fragment size for pcm offload */
#define PCM_OFFLOAD_BUFFER_DURATION_FOR_AV 1000 /* 1 sec */
#define PCM_OFFLOAD_BUFFER_DURATION_FOR_AV_STREAMING 80 /* 80 millisecs */
+#define PCM_OFFLOAD_BUFFER_DURATION_FOR_SMALL_BUFFERS 20 /* 20 millisecs */
+#define PCM_OFFLOAD_BUFFER_DURATION_MAX 1200 /* 1200 millisecs */
/* MAX PCM fragment size cannot be increased further due
* to flinger's cblk size of 1mb,and it has to be a multiple of
@@ -2898,44 +2900,42 @@
uint32_t platform_get_pcm_offload_buffer_size(audio_offload_info_t* info)
{
- uint32_t fragment_size = MIN_PCM_OFFLOAD_FRAGMENT_SIZE;
+ uint32_t fragment_size = 0;
uint32_t bits_per_sample = 16;
+ uint32_t pcm_offload_time = PCM_OFFLOAD_BUFFER_DURATION_FOR_SMALL_BUFFERS;
if (info->format == AUDIO_FORMAT_PCM_24_BIT_OFFLOAD) {
bits_per_sample = 32;
}
- if (!info->has_video) {
- fragment_size = MAX_PCM_OFFLOAD_FRAGMENT_SIZE;
-
- } else if (info->has_video && info->is_streaming) {
- fragment_size = (PCM_OFFLOAD_BUFFER_DURATION_FOR_AV_STREAMING
- * info->sample_rate
- * (bits_per_sample >> 3)
- * popcount(info->channel_mask))/1000;
-
- } else if (info->has_video) {
- fragment_size = (PCM_OFFLOAD_BUFFER_DURATION_FOR_AV
- * info->sample_rate
- * (bits_per_sample >> 3)
- * popcount(info->channel_mask))/1000;
+ if (info->use_small_bufs) {
+ pcm_offload_time = PCM_OFFLOAD_BUFFER_DURATION_FOR_SMALL_BUFFERS;
+ } else {
+ if (!info->has_video) {
+ pcm_offload_time = PCM_OFFLOAD_BUFFER_DURATION_MAX;
+ } else if (info->has_video && info->is_streaming) {
+ pcm_offload_time = PCM_OFFLOAD_BUFFER_DURATION_FOR_AV_STREAMING;
+ } else if (info->has_video) {
+ pcm_offload_time = PCM_OFFLOAD_BUFFER_DURATION_FOR_AV;
+ }
}
- char value[PROPERTY_VALUE_MAX] = {0};
- if((property_get("audio.offload.pcm.buffer.size", value, "")) &&
- atoi(value)) {
- fragment_size = atoi(value) * 1024;
- ALOGV("Using buffer size from sys prop %d", fragment_size);
- }
+ //duration is set to 20 ms worth of stereo data at 48Khz
+ //with 16 bit per sample, modify this when the channel
+ //configuration is different
+ fragment_size = (pcm_offload_time
+ * info->sample_rate
+ * (bits_per_sample >> 3)
+ * popcount(info->channel_mask))/1000;
- fragment_size = ALIGN( fragment_size, 1024);
+ fragment_size = ALIGN (fragment_size, 1024);
if(fragment_size < MIN_PCM_OFFLOAD_FRAGMENT_SIZE)
fragment_size = MIN_PCM_OFFLOAD_FRAGMENT_SIZE;
else if(fragment_size > MAX_PCM_OFFLOAD_FRAGMENT_SIZE)
fragment_size = MAX_PCM_OFFLOAD_FRAGMENT_SIZE;
- ALOGV("%s: fragment_size %d", __func__, fragment_size);
+ ALOGI("PCM offload Fragment size to %d bytes", fragment_size);
return fragment_size;
}