Messages in this thread | | | Date | Sat, 18 Mar 2000 01:24:04 +0800 | From | Chng Tiak-Jung <> | Subject | Portrait Display on Linux |
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Hi,
I am working on a concept terminal that required the LCD display to be running X windows in portrait mode (600x800). At the moment, the approach that I have taken is to take the standard vesafb driver (the system has VESA BIOS support) and allocate a block of memory to use as a portrait framebuffer. Then I used a kernel thread running in the background to copy from this virtual framebuffer to the physical framebuffer (which is in landscape) at regular interval. I ran the standard XF86_FBDev on top of this and it recognizes the framebuffer correctly and run the X windows in portrait mode.
Here's the problem: the copying from one buffer to the other is taking up lots of CPU time (about 30% or more), this causes deteriotion of the system performance. I believe I have already optimized the code substantiately, but the performance still not up to what we want (when we move our stylus on the touch screen at normal handwriting speed, the cursor always trails behind).
Does anyone know what else I can try to get a better performance out of the system? Some people did told me that I should modify the X windows directly to have better performance, but I am quite reluctant due to the complexity and lack of understanding of X server itself. I would be gladful if someone could do that or guide me on doing it.
Thanks a lot!
Regards, T J -- Chng Tiak-Jung tiak-jung.chng@ericsson.com Ericsson Research/Cyberlab Singapore Tel: +65-350-1649 510 Thomson Road, #18-00 Fax: +65-256-2403 SLF Building, Singapore 298135 http://www.ericsson.com/
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