Bug#695594: xserver-xorg-video-radeon: X segfaults when entering OpenGL mode in Minecraft
On 12/11/2012 04:58 AM, Michel Dänzer wrote:
Note that this crash means minecraft is using indirect rendering, which is
undesirable for a local display. Are you intentionally using indirect
rendering? If not, the output of
LIBGL_DEBUG=verbose glxinfo | grep render
might give hints as to why you're not getting direct rendering.
That was enough for me to track it down, albeit only with about four separate
searches of the entire root partition for one string or another.
It turns out to be because an earlier install of the FGLRX driver - I think from
before there was an officially distributed Debian package for it - had modified
/etc/profile to call /etc/ati/ati-fglrx.sh, which in turn would set
LIBGL_DRIVERS_PATH to something like
'/usr/lib/dri:/usr/lib32/dri:/usr/lib64/dri' if the path was not already set.
After commenting out that line from /etc/profile, and rebooting to be sure it
was cleared from the environment, the crash no longer occurs. I plan to also
clear out the other remnants of that old fglrx install when I have time.
Since Debian doesn't appear to set LIBGL_DRIVERS_PATH by default, but also
doesnt place the architecture-native DRI drivers (in this case, r600_dri.so) in
any of those three locations, they weren't being found. That led to fallback to
indirect rendering mode, which apparently led to the crash.
It's not good to crash when using indirect rendering, of course, and I'd be
willing to conduct tests to help track that crash down if desired - but at least
the direct-rendering mode does appear to work properly. (Though I'd like to know
why, judging from the output of glxgears, I seem to get enforced vsync with
radeon but didn't with fglrx... but that's not really related to this bug.)
--
The Wanderer
Warning: Simply because I argue an issue does not mean I agree with any
side of it.
Every time you let somebody set a limit they start moving it.
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