Regression of v4.6-rc vs. v4.5 bisected: a98ee79317b4 "drm/i915/fbc: enable FBC by default on HSW and BDW"

[Daniel Vetter]

On Thu, May 05, 2016 at 10:45:31PM +0200, Stefan Richter wrote:
> On May 05 Stefan Richter wrote:
> > Quoting the changelog of the commit:
> [...]
> >      - Download intel-gpu-tools, compile it, and run:
> >        $ sudo ./tests/kms_frontbuffer_tracking --run-subtest '*fbc-*' 2>&1 | tee fbc.txt
> >        Then send us the fbc.txt file, especially if you get a failure.
> 
> Attached are results of kms_frontbuffer_tracking from current
> intel-gpu-tools.git (intel-gpu-tools-1.14-273-gb4b2ac346c92), taken on
> kernel v4.5.2 and on v4.6-rc5.

> Subtest fbc-1p-primscrn-spr-indfb-fullscreen failed.
> **** DEBUG ****
> (kms_frontbuffer_tracking:2266) DEBUG: Test requirement passed: fbc.can_test
> (kms_frontbuffer_tracking:2266) drmtest-DEBUG: Test requirement passed: is_i915_device(fd) && has_known_intel_chipset(fd)
> (kms_frontbuffer_tracking:2266) igt-fb-DEBUG: igt_create_fb_with_bo_size(width=2560, height=1440, format=0x34325258, tiling=0x100000000000001, size=14745600)
> (kms_frontbuffer_tracking:2266) drmtest-DEBUG: Test requirement passed: is_i915_device(fd) && has_known_intel_chipset(fd)
> (kms_frontbuffer_tracking:2266) drmtest-DEBUG: Test requirement passed: is_i915_device(fd) && has_known_intel_chipset(fd)
> (kms_frontbuffer_tracking:2266) igt-fb-DEBUG: igt_create_fb_with_bo_size(handle=7, pitch=10240)
> (kms_frontbuffer_tracking:2266) igt-draw-DEBUG: Test requirement passed: intel_gen(intel_get_drm_devid(fd)) >= 5
> (kms_frontbuffer_tracking:2266) DEBUG: Rect 0 CRC: pipe:[febb8b20 00000000 00000000 00000000 00000000] sink:[unsupported!]
> (kms_frontbuffer_tracking:2266) igt-draw-DEBUG: Test requirement passed: intel_gen(intel_get_drm_devid(fd)) >= 5
> (kms_frontbuffer_tracking:2266) DEBUG: Calculated CRC: pipe:[2ca73d01 00000000 00000000 00000000 00000000] sink:[unsupported!]
> (kms_frontbuffer_tracking:2266) DEBUG: Test requirement passed: !fbc_not_enough_stolen()
> (kms_frontbuffer_tracking:2266) DEBUG: Calculated CRC: pipe:[2ca73d01 00000000 00000000 00000000 00000000] sink:[unsupported!]
> (kms_frontbuffer_tracking:2266) igt-draw-DEBUG: Test requirement passed: intel_gen(intel_get_drm_devid(fd)) >= 5
> (kms_frontbuffer_tracking:2266) DEBUG: Calculated CRC: pipe:[2ca73d01 00000000 00000000 00000000 00000000] sink:[unsupported!]
> (kms_frontbuffer_tracking:2266) DEBUG: Test requirement passed: !fbc_not_enough_stolen()
> (kms_frontbuffer_tracking:2266) DEBUG: Calculated CRC: pipe:[2ca73d01 00000000 00000000 00000000 00000000] sink:[unsupported!]
> (kms_frontbuffer_tracking:2266) drmtest-DEBUG: Test requirement passed: is_i915_device(fd) && has_known_intel_chipset(fd)
> (kms_frontbuffer_tracking:2266) igt-fb-DEBUG: igt_create_fb_with_bo_size(width=2560, height=1440, format=0x34325258, tiling=0x100000000000001, size=14745600)
> (kms_frontbuffer_tracking:2266) drmtest-DEBUG: Test requirement passed: is_i915_device(fd) && has_known_intel_chipset(fd)
> (kms_frontbuffer_tracking:2266) drmtest-DEBUG: Test requirement passed: is_i915_device(fd) && has_known_intel_chipset(fd)
> (kms_frontbuffer_tracking:2266) igt-fb-DEBUG: igt_create_fb_with_bo_size(handle=7, pitch=10240)
> (kms_frontbuffer_tracking:2266) DEBUG: Calculated CRC: pipe:[febb8b20 00000000 00000000 00000000 00000000] sink:[unsupported!]
> (kms_frontbuffer_tracking:2266) DEBUG: Test requirement passed: !fbc_not_enough_stolen()
> (kms_frontbuffer_tracking:2266) DEBUG: Calculated CRC: pipe:[febb8b20 00000000 00000000 00000000 00000000] sink:[unsupported!]
> (kms_frontbuffer_tracking:2266) igt-core-INFO: Timed out: CRC reading
> ****  END  ****
> Timed out: CRC reading
> Subtest fbc-1p-primscrn-spr-indfb-fullscreen: FAIL (5.876s)

This one failed in both runs. Can you please retest with just that using

# kms_frontbuffer_tracking --run-subtest fbc-1p-primscrn-spr-indfb-fullscreen

Also please boot with drm.debug=0xe and grab the full dmesg of just that
single subtest. There's definitely something going wrong here.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch