ALSA: pcm: Use pcm_lib_apply_appl_ptr() in x32 sync_ptr

snd_pcm_ioctl_sync_ptr_x32() still handles incoming appl_ptr updates
differently from the other SYNC_PTR paths. The native handler and the
32-bit compat handler both pass appl_ptr through pcm_lib_apply_appl_ptr(),
but the x32 handler still writes control->appl_ptr directly.

That direct assignment skips the common appl_ptr validation against
runtime->boundary and also bypasses the substream ack() callback.
This makes the x32 ioctl path behave differently from the native and
compat32 cases, and it can miss the driver notification that explicit
appl_ptr synchronization relies on.

Use pcm_lib_apply_appl_ptr() for x32 too, so appl_ptr updates are
validated consistently and drivers relying on ack() notifications
see the same behavior.

Signed-off-by: Cássio Gabriel <cassiogabrielcontato@gmail.com>
Link: https://patch.msgid.link/20260321-alsa-pcm-x32-sync-ptr-v1-1-02ce655657c6@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/core/pcm_compat.c b/sound/core/pcm_compat.c
index e71f393d3b0185fbf9aa58086a2af9dc3357a507..5313f50f17da5e8cd6527766f566349fa53c0d1f 100644 (file)
--- a/sound/core/pcm_compat.c
+++ b/sound/core/pcm_compat.c
@@ -430,11 +430,13 @@ static int snd_pcm_ioctl_sync_ptr_x32(struct snd_pcm_substream *substream,
        if (!boundary)
                boundary = 0x7fffffff;
        scoped_guard(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)
+                               return err;
+               } else {
                        scontrol.appl_ptr = control->appl_ptr % boundary;
+               }
                if (!(sflags & SNDRV_PCM_SYNC_PTR_AVAIL_MIN))
                        control->avail_min = scontrol.avail_min;
                else