Comment 325 for bug 1140716

(In reply to comment #52)
> Created attachment 76196 [details]
> i915_error_state (kernel 3.8.1 Fedora) with path (write mbox regs twice on
> snb, v2)
>
> I am applied patch "write mbox regs twice on snb, v2" but still have problem
> [drm:i915_hangcheck_hung] *ERROR* Hangcheck timer elapsed... GPU hung

0x00052cc8: 0x18800100: MI_BATCH_BUFFER_START
0x00052ccc: 0x0d59b000: dword 1
0x00052cd0: 0x13000001: MI_FLUSH_DW post_sync_op='no write'
0x00052cd4: 0x000000c4: address
0x00052cd8: 0x00000000: dword
0x00052cdc: 0x00000000: MI_NOOP
0x00052ce0: 0x11000001: MI_LOAD_REGISTER_IMM
0x00052ce4: 0x00002044: dword 1
0x00052ce8: 0x0007a582: dword 2
0x00052cec: 0x11000001: MI_LOAD_REGISTER_IMM
0x00052cf0: 0x00012040: dword 1
0x00052cf4: 0x0007a582: dword 2
0x00052cf8: 0x10800001: MI_STORE_DATA_INDEX
0x00052cfc: 0x00000080: index
0x00052d00: 0x0007a582: dword
0x00052d04: 0x01000000: MI_USER_INTERRUPT

That's only a single LRI per semaphore, the patch wasn't tested.