[Intel-gfx] [PATCH] drm/i915: Add debugfs to read any DPCD register

[Daniel Vetter]

On Thu, Apr 09, 2015 at 02:54:13PM -0700, shuang.he at intel.com wrote:
> Tested-By: Intel Graphics QA PRTS (Patch Regression Test System Contact: shuang.he at intel.com)
> Task id: 6145
> -------------------------------------Summary-------------------------------------
> Platform          Delta          drm-intel-nightly          Series Applied
> PNV                                  276/276              276/276
> ILK                                  302/302              302/302
> SNB                 -21              313/313              292/313
> IVB                                  337/337              337/337
> BYT                                  286/286              286/286
> HSW                                  395/395              395/395
> BDW                                  321/321              321/321
> -------------------------------------Detailed-------------------------------------
> Platform  Test                                drm-intel-nightly          Series Applied
>  SNB  igt at kms_mmio_vs_cs_flip@setplane_vs_cs_flip      DMESG_WARN(4)PASS(3)      DMESG_WARN(1)
> (dmesg patch applied)drm:intel_dp_start_link_train[i915]]*ERROR*too_many_voltage_retries,give_up at too many voltage .* give up
> drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborting at failed to train .* aborting
>  SNB  igt at kms_rotation_crc@primary-rotation      DMESG_WARN(4)PASS(3)      DMESG_WARN(1)
> (dmesg patch applied)drm:intel_dp_start_link_train[i915]]*ERROR*too_many_voltage_retries,give_up at too many voltage .* give up
> drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborting at failed to train .* aborting
>  SNB  igt at pm_rpm@cursor      DMESG_WARN(4)PASS(3)      DMESG_WARN(1)
> (dmesg patch applied)drm:intel_dp_start_link_train[i915]]*ERROR*too_many_voltage_retries,give_up at too many voltage .* give up
> drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborting at failed to train .* aborting
>  SNB  igt at pm_rpm@cursor-dpms      DMESG_WARN(4)PASS(3)      DMESG_WARN(1)
> (dmesg patch applied)drm:intel_dp_start_link_train[i915]]*ERROR*too_many_voltage_retries,give_up at too many voltage .* give up
> drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborting at failed to train .* aborting
>  SNB  igt at pm_rpm@debugfs-forcewake-user      DMESG_WARN(4)PASS(3)      DMESG_WARN(1)
> (dmesg patch applied)drm:intel_dp_start_link_train[i915]]*ERROR*too_many_voltage_retries,give_up at too many voltage .* give up
> drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborting at failed to train .* aborting
>  SNB  igt at pm_rpm@dpms-mode-unset-non-lpsp      DMESG_WARN(4)PASS(3)      DMESG_WARN(1)
> (dmesg patch applied)drm:intel_dp_start_link_train[i915]]*ERROR*too_many_voltage_retries,give_up at too many voltage .* give up
> drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborting at failed to train .* aborting
>  SNB  igt at pm_rpm@dpms-non-lpsp      DMESG_WARN(4)PASS(3)      DMESG_WARN(1)
> (dmesg patch applied)drm:intel_dp_start_link_train[i915]]*ERROR*too_many_voltage_retries,give_up at too many voltage .* give up
> drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborting at failed to train .* aborting
>  SNB  igt at pm_rpm@drm-resources-equal      DMESG_WARN(4)PASS(3)      DMESG_WARN(1)
> (dmesg patch applied)drm:intel_dp_start_link_train[i915]]*ERROR*too_many_voltage_retries,give_up at too many voltage .* give up
> drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborting at failed to train .* aborting
>  SNB  igt at pm_rpm@fences      DMESG_WARN(4)PASS(3)      DMESG_WARN(1)
> (dmesg patch applied)drm:intel_dp_start_link_train[i915]]*ERROR*too_many_voltage_retries,give_up at too many voltage .* give up
> drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborting at failed to train .* aborting
>  SNB  igt at pm_rpm@fences-dpms      DMESG_WARN(4)PASS(3)      DMESG_WARN(1)
> (dmesg patch applied)drm:intel_dp_start_link_train[i915]]*ERROR*too_many_voltage_retries,give_up at too many voltage .* give up
> drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborting at failed to train .* aborting
>  SNB  igt at pm_rpm@gem-execbuf      DMESG_WARN(4)PASS(3)      DMESG_WARN(1)
> (dmesg patch applied)drm:intel_dp_start_link_train[i915]]*ERROR*too_many_voltage_retries,give_up at too many voltage .* give up
> drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborting at failed to train .* aborting
>  SNB  igt at pm_rpm@gem-idle      DMESG_WARN(4)PASS(3)      DMESG_WARN(1)
> (dmesg patch applied)drm:intel_dp_start_link_train[i915]]*ERROR*too_many_voltage_retries,give_up at too many voltage .* give up
> drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborting at failed to train .* aborting
>  SNB  igt at pm_rpm@gem-mmap-cpu      DMESG_WARN(4)PASS(3)      DMESG_WARN(1)
> (dmesg patch applied)drm:intel_dp_start_link_train[i915]]*ERROR*too_many_voltage_retries,give_up at too many voltage .* give up
> drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborting at failed to train .* aborting
>  SNB  igt at pm_rpm@gem-mmap-gtt      DMESG_WARN(4)PASS(3)      DMESG_WARN(1)
> (dmesg patch applied)drm:intel_dp_start_link_train[i915]]*ERROR*too_many_voltage_retries,give_up at too many voltage .* give up
> drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborting at failed to train .* aborting
>  SNB  igt at pm_rpm@gem-pread      DMESG_WARN(4)PASS(3)      DMESG_WARN(1)
> (dmesg patch applied)drm:intel_dp_start_link_train[i915]]*ERROR*too_many_voltage_retries,give_up at too many voltage .* give up
> drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborting at failed to train .* aborting
>  SNB  igt at pm_rpm@i2c      DMESG_WARN(4)PASS(3)      DMESG_WARN(1)
> (dmesg patch applied)drm:intel_dp_start_link_train[i915]]*ERROR*too_many_voltage_retries,give_up at too many voltage .* give up
> drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborting at failed to train .* aborting
>  SNB  igt at pm_rpm@modeset-non-lpsp      DMESG_WARN(4)PASS(3)      DMESG_WARN(1)
> (dmesg patch applied)drm:intel_dp_start_link_train[i915]]*ERROR*too_many_voltage_retries,give_up at too many voltage .* give up
> drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborting at failed to train .* aborting
>  SNB  igt at pm_rpm@modeset-non-lpsp-stress-no-wait      DMESG_WARN(4)PASS(3)      DMESG_WARN(1)
> (dmesg patch applied)drm:intel_dp_start_link_train[i915]]*ERROR*too_many_voltage_retries,give_up at too many voltage .* give up
> drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborting at failed to train .* aborting
>  SNB  igt at pm_rpm@pci-d3-state      DMESG_WARN(4)PASS(3)      DMESG_WARN(1)
> (dmesg patch applied)drm:intel_dp_start_link_train[i915]]*ERROR*too_many_voltage_retries,give_up at too many voltage .* give up
> drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborting at failed to train .* aborting
>  SNB  igt at pm_rpm@reg-read-ioctl      DMESG_WARN(4)PASS(3)      DMESG_WARN(1)
> (dmesg patch applied)drm:intel_dp_start_link_train[i915]]*ERROR*too_many_voltage_retries,give_up at too many voltage .* give up
> drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborting at failed to train .* aborting
>  SNB  igt at pm_rpm@rte      DMESG_WARN(4)PASS(3)      DMESG_WARN(1)
> (dmesg patch applied)drm:intel_dp_start_link_train[i915]]*ERROR*too_many_voltage_retries,give_up at too many voltage .* give up
> drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborting at failed to train .* aborting
> Note: You need to pay more attention to line start with '*'

Something seems wrong with your test infrastructure, I've seen a bunch of
result (from completely unrelated patches) that DP link training is
failing all over the place on snb (and sometimes ilk).

Has someone tripped over the cable?
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch