Hi,
Here's a patch against 2.4.17-pre6 that fixes a bug with the USB audio
channels. The patch is from Jacek Pliszka.
thanks,
greg k-h
diff -Nru a/drivers/usb/audio.c b/drivers/usb/audio.c
--- a/drivers/usb/audio.c Fri Dec 7 17:31:55 2001
+++ b/drivers/usb/audio.c Fri Dec 7 17:31:55 2001
@@ -3362,28 +3362,48 @@
struct usb_device *dev = state->s->usbdev;
unsigned char data[1];
#endif
+ unsigned char nr_logical_channels, i;
usb_audio_recurseunit(state, ftr[4]);
+
+ if (ftr[5] == 0 ) {
+ printk(KERN_ERR "usbaudio: wrong controls size in feature unit
+%u\n",ftr[3]);
+ return;
+ }
+
if (state->nrchannels == 0) {
printk(KERN_ERR "usbaudio: feature unit %u source has no channels\n",
ftr[3]);
return;
}
if (state->nrchannels > 2)
printk(KERN_WARNING "usbaudio: feature unit %u: OSS mixer interface
does not support more than 2 channels\n", ftr[3]);
- if (state->nrchannels == 1 && ftr[0] == 7+ftr[5]) {
- printk(KERN_DEBUG "usbaudio: workaround for Philips camera microphone
descriptor enabled\n");
- mchftr = ftr[6];
- chftr = 0;
- } else {
- if (ftr[0] < 7+ftr[5]*(1+state->nrchannels)) {
- printk(KERN_ERR "usbaudio: unit %u: invalid FEATURE_UNIT
descriptor\n", ftr[3]);
- return;
+
+ nr_logical_channels=(ftr[0]-7)/ftr[5]-1;
+
+ if (nr_logical_channels != state->nrchannels) {
+ printk(KERN_WARNING "usbaudio: warning: found %d of %d logical
+channels.\n", state->nrchannels,nr_logical_channels);
+
+ if (state->nrchannels == 1 && nr_logical_channels==0) {
+ printk(KERN_INFO "usbaudio: assuming the channel found is the
+master channel (got a Philips camera?). Should be fine.\n");
+ } else if (state->nrchannels == 1 && nr_logical_channels==2) {
+ printk(KERN_INFO "usbaudio: assuming that a stereo channel
+connected directly to a mixer is missing in search (got Labtec headset?). Should be
+fine.\n");
+ state->nrchannels=nr_logical_channels;
+ } else {
+ printk(KERN_WARNING "usbaudio: no idea what's going on...,
+contact [EMAIL PROTECTED]\n");
}
- mchftr = ftr[6];
+ }
+
+ /* There is always a master channel */
+ mchftr = ftr[6];
+ /* Binary AND over logical channels if they exist */
+ if (nr_logical_channels) {
chftr = ftr[6+ftr[5]];
- if (state->nrchannels > 1)
- chftr &= ftr[6+2*ftr[5]];
+ for (i = 2; i <= nr_logical_channels; i++)
+ chftr &= ftr[6+i*ftr[5]];
+ } else {
+ chftr = 0;
}
+
/* volume control */
if (chftr & 2) {
ch = getmixchannel(state, getvolchannel(state));
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