Re: Unexpected kernel device dependency for 'vga* at pci?'

[mlelstv%serpens.de@localhost (Michael van Elst)]

kre%munnari.OZ.AU@localhost (Robert Elz) writes:

>  | While doing this, I've discovered that a radeondrmkmsfb0-based kernel 
>  | requires that I retain the
>  |  	vga* at pci? dev ? func ?
>  | line in the configuration, even though no such device is ever attached.

The VGA driver is used very early as a console, this happens before
autoconf and before the driver is really attached. For this you only
need the VGA driver included in the kernel.

The kernel would panic without the vga driver on conventional
hardware, but there is a bug in the code.

If the VGA driver is included, the radeon code will detach and reattach
it as a console. When the VGA driver is not included, nothing like
that happens, and the VGA hardware probably isn't mapped anywhere.

In my (intel, not radeon) driver I detach the VGA console

#if NVGA > 0
        iaa.iaa_console = vga_cndetach() ? true : false;
#else
        iaa.iaa_console = false;
#endif

and then map the hardware and attach a wsdisplay as if no
VGA driver had existed.

-- 
-- 
                                Michael van Elst
Internet: mlelstv%serpens.de@localhost
                                "A potential Snark may lurk in every tree."