[U-Boot] [PATCH 05/14] cfb_console: Fix function console_scrollup

Anatolij Gustschin agust at denx.de
Fri Mar 23 09:47:34 CET 2012


On Thu, 22 Mar 2012 01:58:02 -0700 (PDT)
Pali Rohár <pali.rohar at gmail.com> wrote:
> Do you think that mapped address of framebuffer is only problem?

I wrote that it could be a problem. I do not know much about
your system and U-Boot port and do not know exactly what you
meant by "damaged screen output" and when exactly it happens,
so I can only speculate.

> Why 
> then framebuffer output on n900 screen working without problem if I 
> do NOT read framebuffer memory? Problem with garbaged display output 
> seems happends only for read operations (console_scrollup, negation 
> of pixels for cursor,...) but not for write-only operations (clear 
> console, clear line, set black/white cursror, render fonsts...). I 
> think if there is problem with address space, then garbaged screen 
> should be also for framebuffer write operations...

This is another issue then. Can you test read/write access to
the frame buffer area by available memory commands "cp", "md",
"mm", "cmp"? Can you also verify that reading from frame buffer
area by using these memory commands is not working?


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