Re: SiS/Trident 4DWave sound driver oops

[Tachino Nobuhiro]

Hello,

At 25 Oct 2001 21:45:58 -0400,
Robert Love wrote:
> 
> On Thu, 2001-10-25 at 21:37, Tachino Nobuhiro wrote:
> >   Following patch may fix your oops. Please try.
> 
> Hm, I don't think so.  The last area is marked zero so code can know
> when it ends.  This is common practice.

But the code does not use the last area. this is the code in
ac97_probe_codec().

	id1 = codec->codec_read(codec, AC97_VENDOR_ID1);
	id2 = codec->codec_read(codec, AC97_VENDOR_ID2);
	for (i = 0; i < ARRAY_SIZE(ac97_codec_ids); i++) {
		if (ac97_codec_ids[i].id == ((id1 << 16) | id2)) {
			codec->type = ac97_codec_ids[i].id;
			codec->name = ac97_codec_ids[i].name;
			codec->codec_ops = ac97_codec_ids[i].ops;
			break;
		}
	}
  
If id1 and id2 happen to be 0, it matches the last entry and codec_ops
is set to uncertain value(maybe 0). it may cause the oops in ac97_init_mixer().