[Intel-gfx] [PATCH] drm/i915: Don't do posting reads on getting forcewake

[shuang.he at intel.com]

Tested-By: PRC QA PRTS (Patch Regression Test System Contact: shuang.he at intel.com)
Task id: 5675
-------------------------------------Summary-------------------------------------
Platform          Delta          drm-intel-nightly          Series Applied
PNV                 -1              353/353              352/353
ILK                                  200/200              200/200
SNB                                  400/422              400/422
IVB              +1                 485/487              486/487
BYT                                  296/296              296/296
HSW              +1-2              507/508              506/508
BDW                                  401/402              401/402
-------------------------------------Detailed-------------------------------------
Platform  Test                                drm-intel-nightly          Series Applied
*PNV  igt_gen3_render_linear_blits      PASS(4, M25M23)      CRASH(1, M23)
 IVB  igt_gem_storedw_batches_loop_normal      DMESG_WARN(5, M34M4)PASS(15, M34M4M21)      PASS(1, M21)
*HSW  igt_gem_pwrite_pread_snooped-copy-performance      PASS(2, M40)      DMESG_WARN(1, M40)
 HSW  igt_gem_pwrite_pread_snooped-pwrite-blt-cpu_mmap-performance      DMESG_WARN(1, M40)PASS(18, M40M20)      PASS(1, M40)
*HSW  igt_gem_storedw_loop_blt      PASS(2, M40)      DMESG_WARN(1, M40)
Note: You need to pay more attention to line start with '*'