[Intel-gfx] PANEL_FITTING atom

Lovelace Luquette luquette at bu.edu
Mon Aug 4 15:40:55 CEST 2008


I'm using an Intel i852GM chipset and have a 16:10 aspect ratio LCD.

I'd like to be able to configure the PANEL_FITTING atom introduced in 2.3. 
However, looking through the code, I see that the PANEL_FITTING atom is 
disabled for all of the i8xx chips.  For these chips all I can do is 
accept the default setting of PANEL_FITTING = full.

The code for letterboxing/pillar-boxing seems to be really simple.  (Even 
for i8xx chips, it seems like all we have to do is set PFIT_CONTROL to the 
appropriate mode, then find the drawing offset and store it in 

Is the reason we can't implement the PANEL_FITTING atom for i8xx because 
the i8xx chips don't have the PFIT_CONTROL and PFIT_PGM_RATIOS registers? 
(As a side note: this doesn't seem to be the case since all of the PFIT_* 
registers are declared in i810_regs.h.  As another side note, when I dump 
the chip's registers I see PFIT_CONTROL and PFIT_PGM_RATIOS in the dump.)

I found the register documentation at http://intellinuxgraphics.org for 
965+ chips; is there a similar place to find register documentation for 
older chips or has intel not released that data?

Joe Luquette

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