Comment 2 for bug 1341284

StacktraceTop:
 pushbuf_kref (push=push@entry=0x7f17d21e21f0, bo=0x0, flags=0) at ../../nouveau/pushbuf.c:151
 pushbuf_validate (push=0x7f17d21e21f0, retry=<optimized out>) at ../../nouveau/pushbuf.c:503
 nouveau_pushbuf_validate (push=push@entry=0x7f17d21e21f0) at ../../nouveau/pushbuf.c:749
 nvc0_m2mf_push_linear (nv=0x7f17d263a780, dst=0x7f17d268eb20, offset=768, domain=<optimized out>, size=76, data=0x7f17d26b2840) at ../../../../../../src/gallium/drivers/nouveau/nvc0/nvc0_transfer.c:188
 nouveau_transfer_write (nv=nv@entry=0x7f17d263a780, tx=tx@entry=0x7f17d2c29190, offset=offset@entry=0, size=76) at ../../../../../../src/gallium/drivers/nouveau/nouveau_buffer.c:218