Using VESA to restore display settings on resume

[Ian Dowse]

In message <1109545918.1537.8.camel at localhost>, Vladimir Grebenschikov writes:
>What notebook you have ? I was not such lucky.
>
>I Has SONY VAIO PCG-Z1WA, by zzz it sleeps ok,=20
>With patch it even said about saving VESA data.
>On any key after it is awakes, spin up drive and fan, but screen still
>black (even no backlight), and it is very unlike that I get console back
>(typing has no effect, even when I try to call kdb).
>
>Also if I try this patch with vesa module loaded it just carsh in vm86
>mode on zzz (curproc acpiconf).
>
>Any suggestions are very welcome.

It is probably necessary to get this working with VESA to have much
of a chance of it helping, since otherwise only the basic VGA
registers will be saved and restored.

One possible reason for the vm86 crash is that it appears our VESA
code cannot handle saving more than 4k of state data. Does it make
any difference if you revert the part of the patch that changed
STATE_MOST to STATE_ALL? i.e. change the two uses of STATE_ALL in
vesa.c back to STATE_MOST. I found that with SAVE_MOST, I needed
to switch to X and back before the console would display, but the
backlight did come on immediately.

Ian