Bug 992 - aty128fb sometimes puts garbage on the screen
Summary: aty128fb sometimes puts garbage on the screen
Alias: None
Product: Sisyphus
Classification: Development
Component: kernel24-up (show other bugs)
Version: unstable
Hardware: all Linux
: P4 minor
Assignee: Peter 'Nidd' Novodvorsky
QA Contact:
Depends on:
Reported: 2002-06-11 20:43 MSD by Sergey Vlasov
Modified: 2003-08-25 15:18 MSD (History)
0 users

See Also:

0000992-linux-2.4.18-aty128fb_fix.patch (deleted)
2002-06-11 20:43 MSD, Sergey Vlasov
no flags Details

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Description Sergey Vlasov 2002-06-11 20:43:41 MSD
With kernel24-up-2.4.18-alt6master (and older versions) and aty128fb sometimes there is garbage on the screen (parts of characters, usually in place of spaces).  The effect is sometimes visible in mutt (when sorting by threads and there are many long threads) and very noticeable with the new aptitude (pull down the menu and press Left and Right to move between different submenus).

Looking at the source, I have noted two problems:

1. The driver does not wrap display_switch.{clear,revc} in all color depths, therefore some video memory access might be overlapping with the accelerator.

2. The accelerated bmove function always uses left-to-right and top-to-bottom direction, without checking the actual direction of move. When doing overlapped copies, this causes corruption. (The \"insert characters\" control code, which causes part of the line to be shifted right, triggers the problem.)

I have made a patch against the driver sources included in kernel24-2.4.18-alt6master to fix the problems.  On my system, with the Rage128 Pro card, the fixed driver looks stable.


Comment 1 Bug Reporter 2003-01-08 21:30:42 MSK
in 2.4.20
Comment 2 Bug Reporter 2003-01-08 21:30:42 MSK
in 2.4.20