1 files changed, 22 insertions, 8 deletions

diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index b9517f38073c..4c3edc1532c9 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -3440,14 +3440,28 @@ out:
 #endif /* CONFIG_SND_SUPPORT_OLD_API */
 
 #ifndef CONFIG_MMU
-unsigned long dummy_get_unmapped_area(struct file *file, unsigned long addr,
-                                      unsigned long len, unsigned long pgoff,
-                                      unsigned long flags)
-{
-        return 0;
+static unsigned long snd_pcm_get_unmapped_area(struct file *file,
+                                               unsigned long addr,
+                                               unsigned long len,
+                                               unsigned long pgoff,
+                                               unsigned long flags)
+{
+        struct snd_pcm_file *pcm_file = file->private_data;
+        struct snd_pcm_substream *substream = pcm_file->substream;
+        struct snd_pcm_runtime *runtime = substream->runtime;
+        unsigned long offset = pgoff << PAGE_SHIFT;
+
+        switch (offset) {
+        case SNDRV_PCM_MMAP_OFFSET_STATUS:
+                return (unsigned long)runtime->status;
+        case SNDRV_PCM_MMAP_OFFSET_CONTROL:
+                return (unsigned long)runtime->control;
+        default:
+                return (unsigned long)runtime->dma_area + offset;
+        }
 }
 #else
-# define dummy_get_unmapped_area NULL
+# define snd_pcm_get_unmapped_area NULL
 #endif
 
 /*
@@ -3467,7 +3481,7 @@ const struct file_operations snd_pcm_f_ops[2] = {
                 .compat_ioctl =         snd_pcm_ioctl_compat,
                 .mmap =                 snd_pcm_mmap,
                 .fasync =               snd_pcm_fasync,
-                .get_unmapped_area =    dummy_get_unmapped_area,
+                .get_unmapped_area =    snd_pcm_get_unmapped_area,
         },
         {
                 .owner =                THIS_MODULE,
@@ -3481,6 +3495,6 @@ const struct file_operations snd_pcm_f_ops[2] = {
                 .compat_ioctl =         snd_pcm_ioctl_compat,
                 .mmap =                 snd_pcm_mmap,
                 .fasync =               snd_pcm_fasync,
-                .get_unmapped_area =    dummy_get_unmapped_area,
+                .get_unmapped_area =    snd_pcm_get_unmapped_area,
         }
 };