Comment 40 for bug 1553328

[35345.800105] nouveau E[ PFIFO][0000:01:00.0] DMA_PUSHER - ch 6 [emulator-x86[1371]] get 0x00200f9878 put 0x00200f98d0 ib_get 0x000000ed ib_put 0x000000f6 state 0x80000000 (err: INVALID_CMD) push 0x00406040

This is a long-standing and utterly undiagnosed issue. Somehow an invalid command manages to make it onto the pushbuf. [A command as in a FIFO command, like "BEGIN_NV04" style, not like the actual data being fed to the engine.]

There has never been a reproducible way of triggering it. Only seems to happen on tesla GPUs. Either something *very* subtle is going on in mesa, or we're driving the hardware wrong, or... who knows.

Search around for 406040 -- tons of bugs open about this.