ALSA: pcm - Safer boundary checks

Make the boundary checks a bit safer.
These caese are rare or theoretically won't happen, but nothing
bad to keep the checks safer...

Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 5 insertions, 4 deletions

diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index 063c675177a9..fbb2e391591e 100644
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -222,8 +222,9 @@ static int snd_pcm_update_hw_ptr_interrupt(struct snd_pcm_substream *substream)
         hw_ptr_interrupt = runtime->hw_ptr_interrupt + runtime->period_size;
         delta = new_hw_ptr - hw_ptr_interrupt;
         if (hw_ptr_interrupt >= runtime->boundary) {
-                hw_ptr_interrupt %= runtime->boundary;
-                if (!hw_base) /* hw_base was already lapped; recalc delta */
+                hw_ptr_interrupt -= runtime->boundary;
+                if (hw_base < runtime->boundary / 2)
+                        /* hw_base was already lapped; recalc delta */
                         delta = new_hw_ptr - hw_ptr_interrupt;
         }
         if (delta < 0) {
@@ -241,7 +242,7 @@ static int snd_pcm_update_hw_ptr_interrupt(struct snd_pcm_substream *substream)
                         delta = 0;
                 } else {
                         hw_base += runtime->buffer_size;
-                        if (hw_base == runtime->boundary)
+                        if (hw_base >= runtime->boundary)
                                 hw_base = 0;
                         new_hw_ptr = hw_base + pos;
                 }
@@ -296,7 +297,7 @@ int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream)
                         return 0;
                 }
                 hw_base += runtime->buffer_size;
-                if (hw_base == runtime->boundary)
+                if (hw_base >= runtime->boundary)
                         hw_base = 0;
                 new_hw_ptr = hw_base + pos;
         }