Re: X and intelfb fight over videomode

["Antonino A. Daplas" <adaplas@gmail.com>]

David Härdeman wrote:
> On Thu, Nov 17, 2005 at 09:11:53AM +0800, Antonino A. Daplas wrote:
>> David Härdeman wrote:
>>> intelfb: Changing the video mode is not supported.
> 
>> Try booting with video=intelfb:1024x768-16@60,mtrr=0. Do not include
>> the vga=0x318 option.  This prevents intelfb from changing the videomode.
> 
> It seems that intelfb can't change it no matter what....booting with
> video=intelfb:1024x768-16@60,mtrr=0 gives me the usual vga console and
> no framebuffer. The following is printed during boot:
> 

Ah, okay, you have a flatpanel display, so you really need vesa to program
the mode.


> Suggestions?
> 

The main problem is that when check_var fails, set_par is not called
which means that the ringbuffer is not set up correctly after switching
from X.

Try this first, then we'll think of a definitive solution later.

Open drivers/video/intelfb/intelfbdrv.c and look at intelfb_check_var().

Look for this particular snippet...

	if (FIXED_MODE(dinfo) &&
	    (change_var ||
	     var->yres_virtual > dinfo->initial_var.yres_virtual ||
	     var->yres_virtual < dinfo->initial_var.yres ||
	     var->xoffset || var->nonstd)) {
		if (first) {
			ERR_MSG("Changing the video mode is not supported.\n");
			first = 0;
		}
		return -EINVAL;
	}


And then insert a line so it looks like this:

	if (FIXED_MODE(dinfo) &&
	    (change_var ||
	     var->yres_virtual > dinfo->initial_var.yres_virtual ||
	     var->yres_virtual < dinfo->initial_var.yres ||
	     var->xoffset || var->nonstd)) {
		if (first) {
			ERR_MSG("Changing the video mode is not supported.\n");
			first = 0;
		}
		intelfb_set_par(info); /* insert this line */
		return -EINVAL;
	}