ALSA: compress_core: Rework writes to use cumulative values

This patch reworks the writes to use cumulative values thus making the
app_pointer unecessary and removing it.

Only tested as far as build.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Richard Fitzgerald <rf@opensource.wolfsonmicro.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 11 insertions, 7 deletions

diff --git a/sound/core/compress_offload.c b/sound/core/compress_offload.c
index 36d7688fe69a..7941ace78283 100644
--- a/sound/core/compress_offload.c
+++ b/sound/core/compress_offload.c
@@ -28,11 +28,13 @@
 #include <linux/file.h>
 #include <linux/fs.h>
 #include <linux/list.h>
+#include <linux/math64.h>
 #include <linux/mm.h>
 #include <linux/mutex.h>
 #include <linux/poll.h>
 #include <linux/slab.h>
 #include <linux/sched.h>
+#include <linux/types.h>
 #include <linux/uio.h>
 #include <linux/uaccess.h>
 #include <linux/module.h>
@@ -223,21 +225,24 @@ static int snd_compr_write_data(struct snd_compr_stream *stream,
         void *dstn;
         size_t copy;
         struct snd_compr_runtime *runtime = stream->runtime;
+        /* 64-bit Modulus */
+        u64 app_pointer = div64_u64(runtime->total_bytes_available,
+                                    runtime->buffer_size);
+        app_pointer = runtime->total_bytes_available -
+                      (app_pointer * runtime->buffer_size);
 
-        dstn = runtime->buffer + runtime->app_pointer;
+        dstn = runtime->buffer + app_pointer;
         pr_debug("copying %ld at %lld\n",
-                        (unsigned long)count, runtime->app_pointer);
-        if (count < runtime->buffer_size - runtime->app_pointer) {
+                        (unsigned long)count, app_pointer);
+        if (count < runtime->buffer_size - app_pointer) {
                 if (copy_from_user(dstn, buf, count))
                         return -EFAULT;
-                runtime->app_pointer += count;
         } else {
-                copy = runtime->buffer_size - runtime->app_pointer;
+                copy = runtime->buffer_size - app_pointer;
                 if (copy_from_user(dstn, buf, copy))
                         return -EFAULT;
                 if (copy_from_user(runtime->buffer, buf + copy, count - copy))
                         return -EFAULT;
-                runtime->app_pointer = count - copy;
         }
         /* if DSP cares, let it know data has been written */
         if (stream->ops->ack)
@@ -656,7 +661,6 @@ static int snd_compr_stop(struct snd_compr_stream *stream)
         if (!retval) {
                 stream->runtime->state = SNDRV_PCM_STATE_SETUP;
                 wake_up(&stream->runtime->sleep);
-                stream->runtime->app_pointer = 0;
                 stream->runtime->total_bytes_available = 0;
                 stream->runtime->total_bytes_transferred = 0;
         }