(In reply to Alexandre Demers from comment #21)

> > So currently a bit confused - as reported by Christoph in the other bug, it
> > is possible to have good with vanilla mesa/kernel, but apparently for me the
> > "same" mesa can also be bad.
> > 
> > I did try more clean/rebuild cycles including single thread but am currently
> > still bad.
> 
> I'm also seeing this behavior while bisecting a different bug on a 7950...
> Probably related...

It seems like current mesa doesn't build/install properly when patched without
being totally clean.

The mesa patch in this bug on an already built tree does provoke -

make[3]: Entering directory
'/mnt/sdb1/Src64/Mesa-git/mesa/src/gallium/drivers/radeon'
  CC       r600_buffer_common.lo
  CCLD     libradeon.la

but radeonsi_dri.so is not changed after make install.