ALSA: compress_core: Rework writes to use cumulative values
authorCharles Keepax <ckeepax@opensource.wolfsonmicro.com>
Thu, 18 Apr 2013 10:03:46 +0000 (11:03 +0100)
committerTakashi Iwai <tiwai@suse.de>
Sun, 21 Apr 2013 07:54:11 +0000 (09:54 +0200)
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>
include/sound/compress_driver.h
sound/core/compress_offload.c

index 2d7de9610f114d84974268582502bb8a4196235f..9031a26249b56e1bcc1fde74bde36a5f50dfe463 100644 (file)
@@ -56,7 +56,6 @@ struct snd_compr_runtime {
        u64 buffer_size;
        u32 fragment_size;
        u32 fragments;
-       u64 app_pointer;
        u64 total_bytes_available;
        u64 total_bytes_transferred;
        wait_queue_head_t sleep;
index 36d7688fe69ab0a51c4fe3d0ef21411bcb1a2bc5..7941ace782833e78026cb9c9b8494f27fc8b2d2c 100644 (file)
 #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;
        }