Add warning notes for known quirkly ata chipsets

[Mark Kirkwood]

Do folks think that amending the ata(4) man page, and adding warnings 
beside  known quirky or broken chipsets is a good idea? I'm thinking of 
Si 3112 here in particular(!) - the aim being to discourage folks from 
buying 'em based on the fact they appear in ata(4).

I'm happy to draft up something - altho I'd be pretty basic like:

<patch idea>
Silicon Image:  SiI0680, SiI3112 (see NOTES), SiI3114, SiI3512.

Notes:
....
There have been reports of data corruption and erratic behavior with 
some chipsets. This seems to be related to deficiencies with the chipset 
design rather than the driver code. It is recommended to avoid these. A 
  list of known problematic chipsets is:  SiI3112,...
</patch idea>

I don't know any others offhand - but if a) the basic idea seems 
sensible and b) people mail me with well documented cases, I'd be happy 
to add 'em!

Finally, I'm bringing this up now, as 6.1 is out soon, and it seemed a 
good time :-)


regards

Mark