[PATCH] drm/bochs: Add screen blanking support

[Takashi Iwai]

On Wed, 21 Apr 2021 09:19:42 +0200,
Gerd Hoffmann wrote:
> 
> > > However, a tricky part is that the QEMU vga code does treat VGA_ATT_IW
> > > register always as "flip-flop"; the first write is for index and the
> > > second write is for the data like palette.  Meanwhile, in the current
> > > bochs DRM driver, the flip-flop wasn't considered, and it calls only
> > > the register update once with the value 0x20.
> > > 
> > 
> > Unless bochs does things very different, the index should first be reset by
> > reading 0x3da. Then write the index, then the data.
> > 
> > https://web.stanford.edu/class/cs140/projects/pintos/specs/freevga/vga/vgareg.htm#attribute
> 
> bochs should follow standard vga logic here.
> Also a bochs_set_blank(true/false) helper function probably makes sense.

OK, I factored it out to bochs_hw_blank() in v2 patch.


thanks,

Takashi