ALSA: us122l: Fix signedness in comparisions

Within 2.6.30's mergewindow, struct urb's transfer_buffer_length has become
unsigned. This changed an "int > int" comparision to an "unsigned > int" one
in snd_usb_122l.
Fix this by using a local int variable instead of urb->transfer_buffer_length
in comparisions.

Shorten playback_prep_freqn() a bit and tweak error-paths in
usb_stream_prepare_playback().

Signed-off-by: Karsten Wiese <fzu@wemgehoertderstaat.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/usb/usx2y/usb_stream.c b/sound/usb/usx2y/usb_stream.c
index 24393da..12ae034 100644 (file)
--- a/sound/usb/usx2y/usb_stream.c
+++ b/sound/usb/usx2y/usb_stream.c
@@ -33,32 +33,26 @@ static unsigned usb_stream_next_packet_size(struct usb_stream_kernel *sk)
 static void playback_prep_freqn(struct usb_stream_kernel *sk, struct urb *urb)
 {
        struct usb_stream *s = sk->s;
-       unsigned l = 0;
-       int pack;
-
-       urb->iso_frame_desc[0].offset = 0;
-       urb->iso_frame_desc[0].length = usb_stream_next_packet_size(sk);
-       sk->out_phase = sk->out_phase_peeked;
-       urb->transfer_buffer_length = urb->iso_frame_desc[0].length;
-
-       for (pack = 1; pack < sk->n_o_ps; pack++) {
-               l = usb_stream_next_packet_size(sk);
-               if (s->idle_outsize + urb->transfer_buffer_length + l >
-                   s->period_size)
+       int pack, lb = 0;
+
+       for (pack = 0; pack < sk->n_o_ps; pack++) {
+               int l = usb_stream_next_packet_size(sk);
+               if (s->idle_outsize + lb + l > s->period_size)
                        goto check;
 
                sk->out_phase = sk->out_phase_peeked;
-               urb->iso_frame_desc[pack].offset = urb->transfer_buffer_length;
+               urb->iso_frame_desc[pack].offset = lb;
                urb->iso_frame_desc[pack].length = l;
-               urb->transfer_buffer_length += l;
+               lb += l;
        }
-       snd_printdd(KERN_DEBUG "%i\n", urb->transfer_buffer_length);
+       snd_printdd(KERN_DEBUG "%i\n", lb);
 
 check:
        urb->number_of_packets = pack;
-       s->idle_outsize += urb->transfer_buffer_length - s->period_size;
+       urb->transfer_buffer_length = lb;
+       s->idle_outsize += lb - s->period_size;
        snd_printdd(KERN_DEBUG "idle=%i ul=%i ps=%i\n", s->idle_outsize,
-                   urb->transfer_buffer_length, s->period_size);
+                   lb, s->period_size);
 }
 
 static void init_pipe_urbs(struct usb_stream_kernel *sk, unsigned use_packsize,
@@ -282,21 +276,20 @@ static int usb_stream_prepare_playback(struct usb_stream_kernel *sk,
        struct usb_stream *s = sk->s;
        struct urb *io;
        struct usb_iso_packet_descriptor *id, *od;
-       int p, l = 0;
+       int p = 0, lb = 0, l = 0;
 
        io = sk->idle_outurb;
        od = io->iso_frame_desc;
-       io->transfer_buffer_length = 0;
 
-       for (p = 0; s->sync_packet < 0; ++p, ++s->sync_packet) {
+       for (; s->sync_packet < 0; ++p, ++s->sync_packet) {
                struct urb *ii = sk->completed_inurb;
                id = ii->iso_frame_desc +
                        ii->number_of_packets + s->sync_packet;
                l = id->actual_length;
 
                od[p].length = l;
-               od[p].offset = io->transfer_buffer_length;
-               io->transfer_buffer_length += l;
+               od[p].offset = lb;
+               lb += l;
        }
 
        for (;
@@ -304,38 +297,38 @@ static int usb_stream_prepare_playback(struct usb_stream_kernel *sk,
             ++p, ++s->sync_packet) {
                l = inurb->iso_frame_desc[s->sync_packet].actual_length;
 
-               if (s->idle_outsize + io->transfer_buffer_length + l >
-                   s->period_size)
+               if (s->idle_outsize + lb + l > s->period_size)
                        goto check_ok;
 
                od[p].length = l;
-               od[p].offset = io->transfer_buffer_length;
-               io->transfer_buffer_length += l;
+               od[p].offset = lb;
+               lb += l;
        }
 
 check_ok:
        s->sync_packet -= inurb->number_of_packets;
-       if (s->sync_packet < -2 || s->sync_packet > 0) {
+       if (unlikely(s->sync_packet < -2 || s->sync_packet > 0)) {
                snd_printk(KERN_WARNING "invalid sync_packet = %i;"
                           " p=%i nop=%i %i %x %x %x > %x\n",
                           s->sync_packet, p, inurb->number_of_packets,
-                          s->idle_outsize + io->transfer_buffer_length + l,
-                          s->idle_outsize, io->transfer_buffer_length,  l,
+                          s->idle_outsize + lb + l,
+                          s->idle_outsize, lb,  l,
                           s->period_size);
                return -1;
        }
-       if (io->transfer_buffer_length % s->cfg.frame_size) {
+       if (unlikely(lb % s->cfg.frame_size)) {
                snd_printk(KERN_WARNING"invalid outsize = %i\n",
-                          io->transfer_buffer_length);
+                          lb);
                return -1;
        }
-       s->idle_outsize += io->transfer_buffer_length - s->period_size;
+       s->idle_outsize += lb - s->period_size;
        io->number_of_packets = p;
-       if (s->idle_outsize > 0) {
-               snd_printk(KERN_WARNING "idle=%i\n", s->idle_outsize);
-               return -1;
-       }
-       return 0;
+       io->transfer_buffer_length = lb;
+       if (s->idle_outsize <= 0)
+               return 0;
+
+       snd_printk(KERN_WARNING "idle=%i\n", s->idle_outsize);
+       return -1;
 }
 
 static void prepare_inurb(int number_of_packets, struct urb *iu)