Re: [RFC][AGPGART]intel-agp: save whole config space in suspend/resume

[Wang Zhenyu <zhenyu.z.wang@intel.com>]

On 2007.06.11 22:23:21 +0000, Dave Jones wrote:
> 
> I'd feel much safer if we only did this on chipsets where we know we 
> have to do it.   Doing this for *every* Intel chipset ever made _will_
> bite us.  There are some early chipsets (440BX era iirc) that would just
> hang the box when you tried to read from various write-only registers.
> 
> But even on the chipsets where we _do_ need to save/restore something in
> the upper part of the config space, surely it'd be a lot safer
> to just save/restore what we need to rather than risk all sorts
> of mayhem by writing to bits that may trigger hardware events.
> 

I understand. Before James reported his problem on i915, I have thought
the basic restore on that chip should already be enough, but he proved I was
wrong and I'm not sure if this also happens on other i915 board with different
BIOS. 

And with my patch it has already removed the restore cases for 440BX like type,
coz it's gmch_chip_id == 0 and intel_private.pcidev is NULL, so it won't save
extra space on those chips.