RE: [PATCH] reverse pci config space restore order

From: Brown, Len
Date: Tue Apr 25 2006 - 14:23:59 EST



>On Tue, 2006-04-25 at 11:48 +0100, Matthew Garrett wrote:
>> On Tue, Apr 25, 2006 at 02:50:57PM +0800, Yu, Luming wrote:
>>
>> > - for (i = 0; i < 16; i++)
>> > + for (i = 15; i >= 0 ; i--)
>>
>> We certainly need to do /something/ here, but I'm not sure
>> this is it.
>> Adam Belay has code to limit PCI state restoration to the
>> PCI-specified
>> registers, with the idea being that individual drivers fix things up
>> properly. While this has the obvious drawback that almost every PCI
>> driver in the tree would then need fixing up, it's also probably the
>> right thing.
>
>it has a second drawback: it assumes all devices HAVE a driver, which
>isn't normally the case...

Adam mentioned earlier, and I agree, that it is probably a bad
idea for this code to blindly scribble on the BIST field at i=3.
Probably we should clear that field before restoring it.

Re: this patch
I think that this patch is likely a positive forward step.
It seems logical to restore the BARs before the CMD/STATUS in general,
nothing specific to the ICH here.

But yes, this is a helper routine and devices where it hurts
instead of helps should have their own routine. Complex devices
need to handle the device-specific config space state above these
1st 16 locations anyway.

-Len
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