staging: line6: eliminate useless index_out variable

Playback urbs use the index_out counter to decide which part of the
playback buffer to use.  Since the urb already has a unique index in
range [0, LINE6_ISO_BUFFERS) there is no need to keep a separate
counter.

Use the urb index instead.  This also eliminates the possibility of two
urbs using the same playback buffer space if they ever complete
out-of-order for some reason.

Signed-off-by: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: Markus Grabner <grabner@icg.tugraz.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/staging/line6/pcm.h b/drivers/staging/line6/pcm.h
index 05f4ef3..55d8297 100644 (file)
--- a/drivers/staging/line6/pcm.h
+++ b/drivers/staging/line6/pcm.h
@@ -146,11 +146,6 @@ struct snd_line6_pcm {
        unsigned char *buffer_in;
 
        /**
-                Temporary buffer index for playback.
-       */
-       int index_out;
-
-       /**
                 Previously captured frame (for software monitoring).
        */
        unsigned char *prev_fbuf;

diff --git a/drivers/staging/line6/playback.c b/drivers/staging/line6/playback.c
index b17c0a7..9a51b92 100644 (file)
--- a/drivers/staging/line6/playback.c
+++ b/drivers/staging/line6/playback.c
@@ -192,13 +192,10 @@ static int submit_audio_out_urb(struct snd_line6_pcm *line6pcm)
        urb_frames = urb_size / bytes_per_frame;
        urb_out->transfer_buffer =
            line6pcm->buffer_out +
-           LINE6_ISO_PACKETS * line6pcm->max_packet_size * line6pcm->index_out;
+           index * LINE6_ISO_PACKETS * line6pcm->max_packet_size;
        urb_out->transfer_buffer_length = urb_size;
        urb_out->context = line6pcm;
 
-       if (++line6pcm->index_out == LINE6_ISO_BUFFERS)
-               line6pcm->index_out = 0;
-
        if (test_bit(BIT_PCM_ALSA_PLAYBACK, &line6pcm->flags) &&
            !test_bit(BIT_PAUSE_PLAYBACK, &line6pcm->flags)) {
                struct snd_pcm_runtime *runtime =