drm:pid12:i915_hangcheck_elapsed] *ERROR* Hangcheck timer elapsed... GPU hung

Hello,

After r271705 (probably) I'm getting this error in dmesg:

error: [drm:pid12:i915_hangcheck_elapsed] *ERROR* Hangcheck timer 
elapsed... GPU hung
info: [drm] capturing error event; look for more information in sysctl 
hw.dri.0.info.i915_error_state

The system freezes for a little while.

The "sysctl hw.dri.0.info.i915_error_state" is here: 
https://people.freebsd.org/~danilo/i915.txt

# uname -a
FreeBSD capeta 11.0-CURRENT FreeBSD 11.0-CURRENT #5 r271887: Fri Sep 19 
23:11:02 BRT 2014     danilo_at_capeta:/usr/obj/usr/src/sys/CAPETA amd64

CPU
info: [drm] Initialized drm 1.1.0 20060810
CPU: Intel(R) Core(TM) i3-2310M CPU _at_ 2.10GHz (2095.29-MHz K8-class CPU)
   Origin="GenuineIntel"  Id=0x206a7  Family=0x6  Model=0x2a Stepping=7
Features=0xbfebfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CLFLUSH,DTS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE>
Features2=0x1dbae3bf<SSE3,PCLMULQDQ,DTES64,MON,DS_CPL,VMX,EST,TM2,SSSE3,CX16,xTPR,PDCM,PCID,SSE4.1,SSE4.2,x2APIC,POPCNT,TSCDLT,XSAVE,OSXSAVE,AVX>
   AMD Features=0x28100800<SYSCALL,NX,RDTSCP,LM>
   AMD Features2=0x1<LAHF>
   XSAVE Features=0x1<XSAVEOPT>
   VT-x: (disabled in BIOS) PAT,HLT,MTF,PAUSE,EPT,UG,VPID