[parisc-linux] tentative success with CRX24 framebuffer and X on a 720/50

[Helge Deller]

Hi Steve,

I applied your suggested changes to the CVS kernel 2.4.18-pa38. 
Since I don't have such a graphics card and can't test any changes here, 
please let me know if I did it correctly.

Greetings,
Helge

On Monday 17 June 2002 19:24, Steve Pacenka wrote:
> Friends,
>
> I posted a request for advice about this on the list a couple of weeks
> ago.  The 0.9.3 CD installed well, and then I did a dist-upgrade and
> fiddled with kernel compiles to get fbcon and X going.
>
> 1. Trial and error within the kernel led to two one-line insertions in
> stifb.c (starting with 1.30.2.1 in CVS) enabled CRX24 framebuffer
> (a.k.a. HPA1439A) initialization at 32 bpp and correctly blanked the
> text overlay plane.  Welcome to the penguin and color text.
>
> Change #1: In function
>
>   stifb_init_fb(struct sti_struct *sti, int force_bpp)
>
> of /usr/src/linux/drivers/video/sti/stifb.c insert
>
>   (fb->id != S9000_ID_A1439A) &&
>
> as another line within the #if 1 #endif hack that prevents
> initialization of any but the listed hardware.
>
>
> Change #2: In function
>
>   stifb_set_disp(struct stifb_info *fb)
>
> insert
>
>   ngleClearOverlayPlanes(fb, 0xff, 0);
>
> before the break; within the "clear attribute planes" switch for this
> case.
>
> Change #3: Verify these settings in /usr/src/linux/.config
>
>   CONFIG_FBCON=y
>   CONFIG_FBCON_CFB8=y
>   CONFIG_FBCON_CFB32=y
>   CONFIG_FBCON_STI=y
>
> (CFB8 is for a forthcoming test of 8-bit depth. 24 bits unaccelerated is
> somewhat slow with X on this box.)
>
>
> 2. Telling XF86Config-4 that there is a 32 bit framebuffer having 24 bit
> depth allowed X to start.  Welcome to a Gnome 1.4 splashscreen.
>
>
> Performance of the console framebuffer is not bad, slightly slower than
> the monochrome text that preceded it.  It's nice to have color.  No
> apparent problems with the default font and 24bpp.
>
> Performance under X was better than I expected considering the CPU
> speed, the 24 bit depth, and the non-acceleration.  An 8-bit depth (if
> achievable) and a lighter weight desktop than gnome+sawfish (windowmaker
> perhaps) could get X close to routinely usable.  Except for a frequently
> unresponsive serial mouse (very old M$ mouse) I experienced no basic
> problems within X.
>
> -- thanks, SP