Hi all,
I'm currently having strange problems getting my system to work with my
tv card -- then I read about yout ALI chipset madness. Perhaps any of
you has an idea what's bugging me.
My system is build around the "k7vt2" mainboard by "asrock"
(ASUS-look-a-like) which uses the VIA kt266 (vt8367).
Additionally I'm using nothing spectacular:
- matrox g400 agp gfx card
- western digital 60Gb harddisk
- 256Mb Infineon SD-Ram
Installing RedHat 7.3 and 2.4.20-rc4-ac1 went just fine and the system
is running good so far.
Then I tried to get my tv-card running: it's called "Multimedia
eXtension Board" and is based on the saa7146 chipset by Philips
Semiconductors.
I'm the author of this driver, so I can really look around and see
what's happening inside. http://www.mihu.de/linux/
The problem is, that the overlay mode is not working (ie. write access
via busmaster dma directly to the gfx card's memory).
If I use "xawtv"'s grabdisplay mode, (ie. grab to memory, then display
to screen) the it works.
So, the tv card is basically working and can write via busmaster dma to
the system's main memory.
Now I exchanged the agp card with an old *pci* Diamond Viper 550 card.
This time, the "overlay" mode works!
So, the tv card can write to the gfx card's memory using busmaster dma
over the *pci bus*.
The only thing *not* working is the busmaster dma to the gfx card on the
agp.
Unfortunately, the bios does not provide very much possibilites to tweak
the settings for the whole pci/agp subsystem.
The funny thing is: If I enable overlay: no picture, only black
rectangle. Then I switch to "off" and magically the last frame appears.
So something is preventing direct write access to the gfx card's memory.
Any ideas?
CU
Michael.
