I compiled Mesa with libdrm from their GIT repositories (10.1, commit
2dc35a619c50139d07ad96fc4dfe456e5811c84e). I started up the Second Life viewer
through it (Kokua x64, 3.6.12.30743, Dec 12 2013 05:51:00) and logged in.
Upon enabling Advanced Lighting Model from Preferences - Graphics, the system
froze and the screen started flickering, turning black then recovering every
few seconds. The scene also got covered in pink pixels, meaning it also failed
to render correctly. I was barely able to move the mouse pointer and shut the
viewer down. Once I did, everything returned to normal.
This does not happen with Mesa 9.2.3, and other Graphics options in the viewer
work fine (like "Basic shaders" or "Atmospheric shaders"). Shadows were
disabled and likely not a cause.
If someone has Second Life, please try the deferred lighting system under the
10.1 development version of Mesa. Currently, I don't have any more information
on the problem apart from having experienced the described symptoms.