[Savage40] xv Overlay on crtc2 on SuperSavage (T23) / Argyll display calibration (Resend)

[Alex Deucher]

--- Jon Senior <jon at restlesslemon.co.uk> wrote:

> Resent because I wasn't a member of the list last time so couldn't be
> sure if it was blocked (checking the archives didn't reveal anything
> coming up).
> 
> ------------
> 
> I think the title says it all. ;-) Looking through the archives I
> notice that this got a mention as a known issue, but web searches
> only seem to produce hits dating from 2004/2005. Being as we are now
> in 2008 and this a device likely to lose rather than gain coders, I
> was wondering what the problem actually was.
> 
> The problem in question is that (as best as I can tell) it's not been
> possible to enable the overlay in crtc2.
> 

The mobile savage chips have 2 overlays, one per crtc, and you can even
source both of them to crtc 0.  However, I was never able to get the
second overlay working.  IIRC, the code for the second overlay is in
the driver, I was just never able to get it to work so it's disabled. 
I'm not sure what magic incantation was needed.

> There is also a related issue in that in crtc1 with working overlay,
> video with a horizontal resolution greater than 800 pixels (IIRC)
> shows pink gradient bars from the 801st pixel onwards. This is hard
> to demonstrate as screen grabs using xine / player show the correct
> video.

I recall similar bugs.  I'm not sure what the problem is.  The savage
overlay was one of the most hateful blocks I've ever dealt with. 
Whether or not it would work was often luck.  I suspect there are quite
a few hw errata at work.

> 
> A final query: I was using the Argyll colour management suite to
> calibrate the internal display (It's not very good, but it's now a
> calibrated not-very-good!). Having added a second display (external
> CRT) and set up for xinerama calibration no longer works. I can run
> the software and generate profiles and using dispwin to load the
> profiles doesn't return any errors, but nothing actually changes on
> either display. Does xinerama on SuperSavage do something strange to
> the video LUTs? I ask because I got a similar effect when connecting
> an external display and using Fn-F7 to switch. The first press
> changed nothing, but unloaded the calibration settings.
> 

Due to the way the xserver does gamma correction, it only works in
depth 24, not depth 16.  This was a software limitation, and could
probably have been fixed in the driver, but no one ever got to it.

> Thanks in advance.
> 
> Edit (For resend): I had problems with the scrolling hang in
> xinerama, but adding Option "ShadowStatus" "true" didn't seem to
> solve it. Interestingly, adding that option to both Device sections
> killed xinerama and left me with only the external CRT which has
> perfect xv. I assumed the crtc's would be hardwired. If this is not
> the case, is there a way to specify which one gets used where? Is it
> just screen ordering? I could handle only having xv on the CRT when
> both are enabled. :-)

the crtcs can be routed to any output (fp, dac1, dac2), however the vbe
calls we use to program the crtcs hardcode them (crtc0->lcd,
crtc1->crt).  I had planned to rewrite the driver to program the crtcs
and outputs directly, but never had the time. when you only use one
head, it's always driven by crtc0.

Alex



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