https://bugs.freedesktop.org/show_bug.cgi?id=61182
--- Comment #29 from Marek Olšák maraeo@gmail.com --- r600g crashes because it's mapping a MSAA resource in order to clear the CMASK to zeros. The problem is MSAA resources occupy a lot of memory and the system is failing to map the whole resource.
The solution is easy: we should clear the CMASK and HTILE buffers using DMA or streamout and not with the CPU.