[Intel-gfx] [PATCH 12/12] drm/i915/csr: Simplify stepping computation

[shuang.he at intel.com]

Tested-By: Intel Graphics QA PRTS (Patch Regression Test System Contact: shuang.he at intel.com)
Task id: 6764
-------------------------------------Summary-------------------------------------
Platform          Delta          drm-intel-nightly          Series Applied
ILK                                  303/303              303/303
SNB              +3                 309/316              312/316
IVB                                  343/343              343/343
BYT                 -1              285/285              284/285
HSW              +13                 367/381              380/381
-------------------------------------Detailed-------------------------------------
Platform  Test                                drm-intel-nightly          Series Applied
*SNB  igt at kms_mmio_vs_cs_flip@setcrtc_vs_cs_flip      DMESG_WARN(1)      PASS(1)
*SNB  igt at kms_mmio_vs_cs_flip@setplane_vs_cs_flip      DMESG_WARN(1)      PASS(1)
*SNB  igt at pm_rpm@cursor      DMESG_WARN(1)      PASS(1)
*SNB  igt at pm_rpm@cursor-dpms      DMESG_FAIL(1)      FAIL(1)
*BYT  igt at gem_partial_pwrite_pread@reads-uncached      PASS(1)      FAIL(1)
*HSW  igt at kms_mmio_vs_cs_flip@setplane_vs_cs_flip      DMESG_WARN(1)      PASS(1)
*HSW  igt at pm_lpsp@non-edp      DMESG_WARN(1)      PASS(1)
*HSW  igt at pm_rpm@debugfs-read      DMESG_WARN(1)      PASS(1)
*HSW  igt at pm_rpm@gem-idle      DMESG_WARN(1)      PASS(1)
*HSW  igt at pm_rpm@gem-mmap-gtt      DMESG_WARN(1)      PASS(1)
*HSW  igt at pm_rpm@gem-pread      DMESG_WARN(1)      PASS(1)
*HSW  igt at pm_rpm@i2c      DMESG_WARN(1)      PASS(1)
*HSW  igt at pm_rpm@modeset-non-lpsp      DMESG_WARN(1)      PASS(1)
*HSW  igt at pm_rpm@modeset-non-lpsp-stress-no-wait      DMESG_WARN(1)      PASS(1)
*HSW  igt at pm_rpm@pci-d3-state      DMESG_WARN(1)      PASS(1)
*HSW  igt at pm_rpm@reg-read-ioctl      DMESG_WARN(1)      PASS(1)
*HSW  igt at pm_rpm@rte      DMESG_WARN(1)      PASS(1)
*HSW  igt at pm_rpm@sysfs-read      DMESG_WARN(1)      PASS(1)
Note: You need to pay more attention to line start with '*'