>On Mon, 26 Feb 2001, Michel Dänzer wrote: >> I just had an interesting idea: The flat panel code could never >determine the >> panel dimensions because our machines don't have a BIOS. So I specified them >> with >> >> Option "PanelWidth" "1024" >> Option "PanelHeight" "768" >> >> and it works without any of the options I have mentioned here a thousand >> times! (iBook users will have to use 800 and 600 of course) This kind of >> enables mode switching, but everyone should be aware that *this may damage >> your panel* . You've been warned. >> >> >> Now I just wonder if we could detect the panel dimensions somehow... > >From the OF device tree? And return it to userspace using a new fbdev ioctl()?
Unfortunately, the OF ATI drivers won't give you anything useful in the device-tree (not even the PLL & clock values). There should probably be a way to probe the panel type, but I'm not too sure how. For the PLL & clock values, the only solution I have (suggested by ATI) would be to build a big table indexed by the OF name of the card that contains the ref clocks (the divider can be read from the registers) and eventually the min/max PLL values. A table based on the machine model can probably be used for the LCD size (but beware that wallstreet exist in both 800x600 passive matrix and 1024x768 active & passive matrix). I beleive new LVDS displays can be probed but I don't know how. You can't even rely on the resolution returned by the OF driver as, at least on my pismo, it's able to use a scaled mode for booting if asked to do so by the nvram settings. I tried the above options and indeed, it works. However, if I then allow X to use 800x600 (and other resolutions like 640x480), the scaler doesn't seem to be properly configured. It's readable, but the display is somewhat clipped and have a vertical band at the 3/4 of the screen that wraps part of it. (Difficult to explain what I see... doesn't look far from beeing correct however). I used XF 4.0.2 from the DRI PCIGART branch. Ben.
