[Linux-fbdev-devel] Re: 2.5 fbdev & driver initial mode

[James S. <jsi...@in...>]

> How is a driver supposed to set the default mode on init lately ?
> 
> Looking at rivafb, it fills info->var from fb_find_mode with the mode
> option if any, but then does nothing with it (and does nothing if
> no mode option is passed).
> 
> On radeonfb, I fill a var  with the default mode obtained
> from EDID or the option if any. Then, I basically do
> 
> 	info->var = var;
> 	var.activate = FB_ACTIVATE_NOW;
> 	fb_set_var(&var, info);
> 
> before calling register_framebuffer.
> 
> What is the right way to do ?

Sorry about the confusion. The answer depends on the driver. For the 
rivafb driver because it has a VGA core we have it NOT switch to a 
graphics state. The reason is 


1) If we run a /dev/fb app was can save the hardware text mode state and
    restore it on closing /dev/fb. You can see this in rivafb_open and
   rivafb_release. 

2) We can test loading it as a module as see debugging info while still
   having a VGA text mode. Makes life a little easier. The other thing 
   I like to do is run mdacon and just the fbdev driver by itself. I can 
   then test the fbdev driver. When I get really brave I test fbcon.c and
   can debug it.

Now for graphics hardware built in that has no hardware text mode. It is 
better to set the video mode right away.