Re: uaudio: fix detection of a bunch of logitech webcams

[Remco]

@@ -1814,6 +1827,10 @@
        sc->sc_audio_rev = UGETW(acdp->bcdADC);
        DPRINTFN(2,("%s: found AC header, vers=%03x, len=%d\n",
                 __func__, sc->sc_audio_rev, aclen));
+
+       /* Some webcams descriptors advertise an off-by-one wTotalLength */
+       if (sc->sc_quirks & UAUDIO_FLAG_BAD_ADC_LEN)
+               aclen++;
  
  	sc->sc_nullalt = -1;
  



I'm not in a position to test yet, but I have a comment on the aclen 
usage. AFAICS aclen is used in two places with the fix in between:

        aclen = UGETW(acdp->wTotalLength);
        if (offs + aclen > size)
                return (USBD_INVAL);
...
        if (sc->sc_quirks & UAUDIO_FLAG_BAD_ADC_LEN)
                aclen++;
...
        ibufend = ibuf + aclen;

It looks more correct to fix aclen first, but does that still work ?
e.g.:
        aclen = UGETW(acdp->wTotalLength);
        if (sc->sc_quirks & UAUDIO_FLAG_BAD_ADC_LEN)
                aclen++;
        if (offs + aclen > size)
                return (USBD_INVAL);
...
        ibufend = ibuf + aclen;