Re: [Linux-fbdev-devel] [PATCH 4/5][RFC] fbdev: Clean up framebuffer initialization

On Sun, 5 Sep 2004, Antonino A. Daplas wrote:

On Sunday 05 September 2004 17:16, Geert Uytterhoeven wrote:

quoted

On Sat, 4 Sep 2004, Antonino A. Daplas wrote:

quoted

Currently, the framebuffer system is initialized in a roundabout manner.
First, drivers/char/mem.c calls fbmem_init().  fbmem_init() will then
iterate over an array of individual drivers' xxxfb_init(), then each
driver registers its presence back to fbmem.  During console_init(),
drivers/char/vt.c will call fb_console_init(). fbcon will check for
registered drivers, and if any are present, will call take_over_console()
in drivers/char/vt.c.

This patch changes the initialization sequence so it proceeds in this
manner: Each driver has its own module_init(). Each driver calls
register_framebuffer() in fbmem.c. fbmem.c will then notify fbcon of the
driver registration.  Upon notification, fbcon calls take_over_console()
in vt.c.

My main concern with this change is that it will be no longer possible to
change initialization order (and hence choose the primary display for
systems with multiple graphics adapters) by specifying `video=xxxfb' on the
kernel command line.

I see your point.  But, can we use "fbcon=" setup options to choose which fb
gets mapped to what console? We already have fbcon=map:<option> so we can
choose which becomes the primary display. Granted the "fbcon=" setup is
currently broken, but if fixed, will that be a fair compromise?

Yes, sounds fine.

Just thinking of something else: right now it's possible to disable a fbdev by
saying `video=xxxfb:off'. This can be useful if the fbdev driver doesn't work
with your hardware. After you change, individual fbdev drivers will have to
reimplement this theirselves in their __setup() functions.

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds