Experimental options

[Vladimir Dergachev]

Hi all,

     I would like to get some feedback on what people think
about introducing "experimental" options in the video drivers
and having a standardized way of marking them as such.

     In particular, I thought about classifying as "experimental"
any options that turn on behaviour that can result in lockup or
breakage of standard protocols.

     I would propose that all such options be prefixed with "X_"
and default of "false" (for obvious reasons). It'd be nice to have
a webpage (and/or README) that explains that all options starting
with "X_" are experimental and users turn them on at their own risk.

     For example, I would like to add an option to radeon driver
to enable 3d for R300 cards with non-existent "r300_dri.so" mesa driver.
The reason this is useful is that such trick greatly accelerates 3d on
large resolution screens as 2d driver can also use DRM driver and this 
works perfectly well. This also facilitates work on 3d driver.

     The 2d speedup is quite considerable, however one would expect all GL
apps to break because of this, as even software rendering won't work.

     Again, such feature would be disabled in default configuration.

     So what does everyone think ?

                         best

                           Vladimir Dergachev