Re: [9front] strange behaviour of igfx and vesa

[kokamoto@hera.eonet.ne.jp]

> I'm still experimenting this, but no success.

I think I did all I can do now, but not success.
Then, I'll post my results here for memory of someone else.

I added codes below to ensure the VBLANK timing to enable
Analog Display port according to the manual, like:
in load() function of igfx.c
------- from here-----
	/* program ports */
	if(igfx->pci->did == 0x29a2){		/* K.Okamoto */
		igfx->adpa.v |= 1<<31;		/* enable adpa */
		wr(igfx, igfx->adpa.a, igfx->adpa.v);
		igfx->adpa.v |= 3<<10;		/* disable hsync/vsync */
		wr(igfx, igfx->adpa.a, igfx->adpa.v);
		wr(igfx, 0x070024, 0x207);
		while((rr(igfx, 0x070024) & 1<<9) == 0)
			{/* wait for VSYNC */
		}
		wr(igfx, 0x070024, 0x207);
		while((rr(igfx, 0x070024) & 1<<9) == 0)
			{/* wait for VSYNC */
		}
	}
	igfx->adpa.v &= ~(3<<10);	/* Monitor DPMS: on */
------to here-------

After somewhat longer period to wait the panel shouws no signal,
this fails to show screen.  
Here, I got 0x207 or 0x4 etc on 0x70024 register after the wait loop,
which means above loops work right.

Next, I compared the two dump.rc (using mmio.all), one of which
is done after vesa --> aux/vga -m igfx -l 1680x1050x32
(this case works fine), and the other is done after boot the
terminal without aux/vga.   Then, on the CGA console, I did the comand,
aux/vga -m igfx -l 1680x1050x32; dump.rc | pretty.rc >regdump.

The two register outputs were all the same without one value of
rmmio 00070000, which is not important here.
Therefore, I concluded the difference comes from neither the
settings of registers nor VSYNC problem.   
Therefore, there should be something not written in the manual.

I can use this terminal by booting vesa mode, then
aux/vga -m igfx -l 1680x1050x32, which may be OK now.

Kenji