Re: [PATCH] More i8042-reset quirks for MSI Wind-clone netbooks

[Matthew Garrett <mjg59@srcf.ucam.org>]

On Thu, Jun 18, 2009 at 08:08:09AM +0800, Li, Yan wrote:
> On Wed, Jun 17, 2009 at 03:51:01AM +0100, Matthew Garrett wrote:
> > On Wed, Jun 17, 2009 at 09:01:40AM +0800, Li, Yan I wrote:
> > > This seems a change too aggressive for me. Do we have a good reason
> > > for taking this risk? 
> > 
> > It's generally much easier to find regressions (people complain) than it 
> > is to find things that have never worked (people just assume Linux is 
> > broken).
> 
> That's true. But we are not sure how many regressions we'll meet and
> whether the efforts devoted to handle them is worthy. (How to handle
> regressions? Perhaps, ironically, we'll need another 'whitelist' for
> them!)

If we hit regressions then it's the wrong fix and would have to be 
reverted. Better a small blacklist than a large whitelist (though, in 
the general case, the presence of either is an indication of a bug)

> > > Of course if we found the "actual problem" we'd conjure up a better 
> > > fix. But before that, I'd prefer the conservative way.
> > 
> > Does stock Windows work on the machine? I think this really ought to be 
> > a pretty obvious minimal test before adding quirks to the kernel.
> 
> Does this matter?  Does whether Windows fail or not affect our
> decision here?  (Worse that I have no "stock Windows XP" for
> testing. All I have are those companion Windows Recovery CDs that
> include all drivers).

Yes. If Windows works without hardware specific drivers then there's a 
flaw in our i8042 setup code that's affecting an unknown number of 
machines, and adding more entries to a static table tells us nothing 
about what proportion of those machines are now fixed - it just tells us 
that we've worked around the issue for the ones that Intel happen to be 
testing.

-- 
Matthew Garrett | mjg59@srcf.ucam.org