1 files changed, 15 insertions, 8 deletions

diff --git a/drivers/staging/line6/pcm.c b/drivers/staging/line6/pcm.c
index 02f77d74809f..4795f1284906 100644
--- a/drivers/staging/line6/pcm.c
+++ b/drivers/staging/line6/pcm.c
@@ -107,11 +107,15 @@ static bool test_flags(unsigned long flags0, unsigned long flags1,
 
 int line6_pcm_acquire(struct snd_line6_pcm *line6pcm, int channels)
 {
-        unsigned long flags_old =
-            __sync_fetch_and_or(&line6pcm->flags, channels);
-        unsigned long flags_new = flags_old | channels;
-        unsigned long flags_final = flags_old;
-        int err = 0;
+        unsigned long flags_old, flags_new, flags_final;
+        int err;
+
+        do {
+                flags_old = ACCESS_ONCE(line6pcm->flags);
+                flags_new = flags_old | channels;
+        } while (cmpxchg(&line6pcm->flags, flags_old, flags_new) != flags_old);
+
+        flags_final = flags_old;
 
         line6pcm->prev_fbuf = NULL;
 
@@ -197,9 +201,12 @@ pcm_acquire_error:
 
 int line6_pcm_release(struct snd_line6_pcm *line6pcm, int channels)
 {
-        unsigned long flags_old =
-            __sync_fetch_and_and(&line6pcm->flags, ~channels);
-        unsigned long flags_new = flags_old & ~channels;
+        unsigned long flags_old, flags_new;
+
+        do {
+                flags_old = ACCESS_ONCE(line6pcm->flags);
+                flags_new = flags_old & ~channels;
+        } while (cmpxchg(&line6pcm->flags, flags_old, flags_new) != flags_old);
 
         if (test_flags(flags_new, flags_old, LINE6_BITS_CAPTURE_STREAM))
                 line6_unlink_audio_in_urbs(line6pcm);