ALSA: compress_core: Deconstify copy callback buffer

The buffer passed to the copy callback should not be const because the
copy callback can be used for capture and playback.

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>

3 files changed, 7 insertions, 5 deletions

diff --git a/include/sound/compress_driver.h b/include/sound/compress_driver.h
index ff6c74153fa1..db8273a5175a 100644
--- a/include/sound/compress_driver.h
+++ b/include/sound/compress_driver.h
@@ -121,7 +121,7 @@ struct snd_compr_ops {
         int (*trigger)(struct snd_compr_stream *stream, int cmd);
         int (*pointer)(struct snd_compr_stream *stream,
                         struct snd_compr_tstamp *tstamp);
-        int (*copy)(struct snd_compr_stream *stream, const char __user *buf,
+        int (*copy)(struct snd_compr_stream *stream, char __user *buf,
                        size_t count);
         int (*mmap)(struct snd_compr_stream *stream,
                         struct vm_area_struct *vma);
diff --git a/sound/core/compress_offload.c b/sound/core/compress_offload.c
index 1f69863a83d2..52ca4cce1462 100644
--- a/sound/core/compress_offload.c
+++ b/sound/core/compress_offload.c
@@ -272,10 +272,12 @@ static ssize_t snd_compr_write(struct file *f, const char __user *buf,
         if (avail > count)
                 avail = count;
 
-        if (stream->ops->copy)
-                retval = stream->ops->copy(stream, buf, avail);
-        else
+        if (stream->ops->copy) {
+                char __user* cbuf = (char __user*)buf;
+                retval = stream->ops->copy(stream, cbuf, avail);
+        } else {
                 retval = snd_compr_write_data(stream, buf, avail);
+        }
         if (retval > 0)
                 stream->runtime->total_bytes_available += retval;
 
diff --git a/sound/soc/soc-compress.c b/sound/soc/soc-compress.c
index 29093a306ea2..da83e5658f62 100644
--- a/sound/soc/soc-compress.c
+++ b/sound/soc/soc-compress.c
@@ -315,7 +315,7 @@ static int soc_compr_pointer(struct snd_compr_stream *cstream,
 }
 
 static int soc_compr_copy(struct snd_compr_stream *cstream,
-                          const char __user *buf, size_t count)
+                          char __user *buf, size_t count)
 {
         struct snd_soc_pcm_runtime *rtd = cstream->private_data;
         struct snd_soc_platform *platform = rtd->platform;