hal: Fix alignement of of buffer sent to DSP
Currently, ALIGN macro can align properly only if the buffer size
is a power of 2.
To have same PCM samples for all channels, the buffer size requires to
be multiple of (number of channels * bytes per sample).
For writes to succeed, the buffer must be written at address which is
multiple of 32.
Alignment of 96 satsfies both of the above requirements.
Change-Id: I55d261092925ee1fc57df6954ff40ac4f77494db
diff --git a/hal/msm8916/platform.c b/hal/msm8916/platform.c
index 6014b09..56eb61c 100644
--- a/hal/msm8916/platform.c
+++ b/hal/msm8916/platform.c
@@ -86,7 +86,8 @@
#define MIN_COMPRESS_PASSTHROUGH_FRAGMENT_SIZE (2 * 1024)
#define MAX_COMPRESS_PASSTHROUGH_FRAGMENT_SIZE (8 * 1024)
-#define ALIGN( num, to ) (((num) + (to-1)) & (~(to-1)))
+#define DIV_ROUND_UP(x, y) (((x) + (y) - 1)/(y))
+#define ALIGN(x, y) ((y) * DIV_ROUND_UP((x), (y)))
/*
* This file will have a maximum of 38 bytes:
*
@@ -3273,12 +3274,15 @@
* info->sample_rate
* (bits_per_sample >> 3)
* popcount(info->channel_mask))/1000;
- // align with LCM of 2, 4, 6, 8
- fragment_size = ALIGN( fragment_size, 24 );
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;
+ // To have same PCM samples for all channels, the buffer size requires to
+ // be multiple of (number of channels * bytes per sample)
+ // For writes to succeed, the buffer must be written at address which is multiple of 32
+ // Alignment of 96 satsfies both of the above requirements
+ fragment_size = ALIGN(fragment_size, 96);
ALOGI("PCM offload Fragment size to %d bytes", fragment_size);
return fragment_size;