[Linux-fbdev-devel] Re: fbcon scrolling madness + fbset corruption

[Russell K. <rm...@ar...>]

No one's commented on this yet.

James?

On Sun, Feb 02, 2003 at 07:57:44PM +0000, Russell King wrote:
> This doesn't appear to solve the ywrap problem - I still get
> places where the screen doesn't scroll.  I decided to write a
> small program to dump out the contents of fb_var_screeninfo, and
> where stuff goes horribly wrong:
> 
> bash-2.04# ./tst
> Visible: 1280x1024
> Virtual: 1280x1632
> BPP    : 8
> Offset : +0+2352
> bash-2.04# ./tst
> Visible: 1280x1024
> Virtual: 1280x1632
> BPP    : 8
> Offset : +0+2392
> 
> Up to the point where it goes wrong:
> 
> bash-2.04# ./tst
> Visible: 1280x1024
> Virtual: 1280x1632
> BPP    : 8
> Offset : +0+528
> bash-2.04# ./tst
> Visible: 1280x1024
> Virtual: 1280x1632
> BPP    : 8
> Offset : +0+568
> bash-2.04# ./tst
> Visible: 1280x1024	<--- this is the last line on the screen
> Virtual: 1280x1632
> BPP    : 8
> Offset : +0+608
> bash-2.04#
> 
> So it looks like something isn't limiting the yoffset in the generic
> console layer; an xoffset of 2392 when the maximum virtual Y is 1632
> is just nonsense.
> 
> I also noticed an additional problem with fbcon: if I change the
> resolution using fbset, the change occurs, except I end up with
> corrupted mess on the screen (the reminents of the original display.)
> The shell prompt is nowhere to be seen.
> 
> Hitting ^L clears the screen and then the shell prompt is visiable.

-- 
Russell King (rm...@ar...)                The developer of ARM Linux
             http://www.arm.linux.org.uk/personal/aboutme.html