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>

1 files changed, 30 insertions, 37 deletions

diff --git a/sound/usb/usx2y/usb_stream.c b/sound/usb/usx2y/usb_stream.c
index 24393dafcb6..12ae0340adc 100644
--- 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)