ALSA: seq: correctly detect input buffer overflow

commit 21fd3e956ee8a307a06bc6e095f5767a00eb2a7e upstream.

snd_seq_event_dup returns -ENOMEM in some buffer-full conditions,
but usually returns -EAGAIN. Make -EAGAIN trigger the overflow
condition in snd_seq_fifo_event_in so that the fifo is cleared
and -ENOSPC is returned to userspace as stated in the alsa-lib docs.

Signed-off-by: Adam Goode <agoode@google.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/sound/core/seq/seq_fifo.c b/sound/core/seq/seq_fifo.c
index 490b697..e4389f1 100644 (file)
--- a/sound/core/seq/seq_fifo.c
+++ b/sound/core/seq/seq_fifo.c
@@ -127,7 +127,7 @@ int snd_seq_fifo_event_in(struct snd_seq_fifo *f,
        snd_use_lock_use(&f->use_lock);
        err = snd_seq_event_dup(f->pool, event, &cell, 1, NULL); /* always non-blocking */
        if (err < 0) {
-               if (err == -ENOMEM)
+               if ((err == -ENOMEM) || (err == -EAGAIN))
                        atomic_inc(&f->overflow);
                snd_use_lock_free(&f->use_lock);
                return err;