[BUG] unsafe reset in ac97_codec.c

[Liam Girdwood]

Hi

Does anyone know why ac97_codec.c does a register reset of the codec
during device probing. i.e.

/* probing AC97 codec, AC97 2.0 says that bit 15 of register 0x00
(reset) should 
* be read zero.
*
* FIXME: is the following comment outdated?  -jgarzik 
* Probing of AC97 in this way is not reliable, it is not even SAFE !!
*/
codec->codec_write(codec, AC97_RESET, 0L);


IMO, this is unsafe because it can also reset the codec into it's
default power state which can be "power down". This is not normally a
problem for PC's, but some battery powered devices have the default
codec state as "power down" to conserve power.

Was this introduced as a workaround for some buggy device ?
If no one objects I'll submit a patch.

Liam

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