[Xorg] Any chance i810 driver not rely in vbios to get video modes ?

Francisco Figueiredo Jr. fxjrlists at yahoo.com.br
Fri Aug 6 21:52:06 PDT 2004

Keith Packard wrote:
> Around 0 o'clock on Aug 7, "Francisco Figueiredo Jr." wrote:
>>I have a laptop which is capable of geting 1400x1050, but my bios 
>>doesn't present this mode to i810 driver.
> I've seen kludges around that make this work; you might poke about a bit 
> and report back if you find something that does the trick for you.

Hi Keith Packard!

I found one. It is 855resolution. http://perso.wanadoo.fr/apoirier/ It 
worked and I could get the resolution, but I also got the following 
message in xorg.log:

(II) I810(0): Mode bandwidth is 88 Mpixel/s
(II) I810(0): maxBandwidth is 1152 Mbyte/s, pipe bandwidths are 164 
Mbyte/s, 0 Mbyte/s
(II) I810(0): LFP compensation mode: 0x6
(II) I810(0): Using XFree86 Acceleration Architecture (XAA)
     Screen to screen bit blits
     Solid filled rectangles
     8x8 mono pattern filled rectangles
     Indirect CPU to Screen color expansion
     Solid Horizontal and Vertical Lines
     Offscreen Pixmaps
     Setting up tile and stipple cache:
         32 128x128 slots
         18 256x256 slots
(==) I810(0): Backing store disabled
(==) I810(0): Silken mouse enabled
(II) I810(0): Initializing HW Cursor
(**) Option "dpms"
(**) I810(0): DPMS enabled
(WW) I810(0): Disabling XVideo output because the mode pixel rate (88 MHz)
     exceeds the hardware limit (79 MHz)

What does this mode pixel rate means?

Can this damage my lcd?

Is there someway I can lower this bandwidth without lowering resolution?

In 1280x1024 the mode pixel rate is 78 Mhz.

If no problem exist, the only affected things would be the blue screen 
when viewing movies?

>>Is there any chance i810 driver not rely in bios to program video modes?
> Nope.  Turns out it's "hard" because the i810 doesn't actually contain all 
> of the hardware needed to drive the display -- half of it is in an 
> external chip, and there are *many* possible chips for that job, none of 
> which are made by Intel and none of which have opened up their 
> documentation.
> So, we have to rely on the BIOS to set up those external chips.

hmmmm, ok. I noticed some companies do commercial xwindows drivers and I 
found one which does the i810 programming without relying in vbios.
I wish docs about that could be made public so xorg guys could develop 
the driver :)

Thanks in advance.


Francisco Figueiredo Jr.

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