[PATCH] ALSA: core: Call substream ack() method upon compat mmap, commit

[Alan Young <consult.awy@gmail.com>]

If a 32-bit application is being used with a 64-bit kernel and is using
the mmap mechanism to write data, then the SNDRV_PCM_IOCTL_SYNC_PTR
ioctl results in calling snd_pcm_ioctl_sync_ptr_compat(). Make this use
pcm_lib_apply_appl_ptr() so that the substream's ack() method, if
defined, is called.

The snd_pcm_sync_ptr() function, used in the 64-bit ioctl case, already
uses snd_pcm_ioctl_sync_ptr_compat().

Signed-off-by: Alan Young <consult.awy@gmail.com>
---
  sound/core/pcm_native.c | 11 ++++++++---
  1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index 17a85f4815d5..91a749835ca1 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -3057,9 +3057,14 @@ static int snd_pcm_ioctl_sync_ptr_compat(struct 
snd_pcm_substream *substream,
          boundary = 0x7fffffff;
      snd_pcm_stream_lock_irq(substream);
      /* FIXME: we should consider the boundary for the sync from app */
-    if (!(sflags & SNDRV_PCM_SYNC_PTR_APPL))
-        control->appl_ptr = scontrol.appl_ptr;
-    else
+    if (!(sflags & SNDRV_PCM_SYNC_PTR_APPL)) {
+        err = pcm_lib_apply_appl_ptr(substream,
+                scontrol.appl_ptr);
+        if (err < 0) {
+            snd_pcm_stream_unlock_irq(substream);
+            return err;
+        }
+    } else
          scontrol.appl_ptr = control->appl_ptr % boundary;
      if (!(sflags & SNDRV_PCM_SYNC_PTR_AVAIL_MIN))
          control->avail_min = scontrol.avail_min;
-- 
2.31.1