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

[Daniel Vetter]

On Fri, Apr 10, 2015 at 08:06:41AM +0000, He, Shuang wrote:
> > -----Original Message-----
> > From: Daniel Vetter [mailto:daniel.vetter at ffwll.ch] On Behalf Of Daniel
> > Vetter
> > Sent: Friday, April 10, 2015 3:39 PM
> > To: He, Shuang
> > Cc: Gao, Ethan; intel-gfx at lists.freedesktop.org; R, Durgadoss
> > Subject: Re: [Intel-gfx] [PATCH] drm/i915: Add debugfs to read any DPCD
> > register
> > 
> > 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_ret
> > ries,give_up at too many voltage .* give up
> > >
> > drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborti
> > ng 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_ret
> > ries,give_up at too many voltage .* give up
> > >
> > drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborti
> > ng 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_ret
> > ries,give_up at too many voltage .* give up
> > >
> > drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborti
> > ng 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_ret
> > ries,give_up at too many voltage .* give up
> > >
> > drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborti
> > ng 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_ret
> > ries,give_up at too many voltage .* give up
> > >
> > drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborti
> > ng 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_ret
> > ries,give_up at too many voltage .* give up
> > >
> > drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborti
> > ng 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_ret
> > ries,give_up at too many voltage .* give up
> > >
> > drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborti
> > ng 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_ret
> > ries,give_up at too many voltage .* give up
> > >
> > drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborti
> > ng 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_ret
> > ries,give_up at too many voltage .* give up
> > >
> > drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborti
> > ng 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_ret
> > ries,give_up at too many voltage .* give up
> > >
> > drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborti
> > ng 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_ret
> > ries,give_up at too many voltage .* give up
> > >
> > drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborti
> > ng 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_ret
> > ries,give_up at too many voltage .* give up
> > >
> > drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborti
> > ng 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_ret
> > ries,give_up at too many voltage .* give up
> > >
> > drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborti
> > ng 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_ret
> > ries,give_up at too many voltage .* give up
> > >
> > drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborti
> > ng 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_ret
> > ries,give_up at too many voltage .* give up
> > >
> > drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborti
> > ng 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_ret
> > ries,give_up at too many voltage .* give up
> > >
> > drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborti
> > ng 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_ret
> > ries,give_up at too many voltage .* give up
> > >
> > drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborti
> > ng 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_ret
> > ries,give_up at too many voltage .* give up
> > >
> > drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborti
> > ng 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_ret
> > ries,give_up at too many voltage .* give up
> > >
> > drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborti
> > ng 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_ret
> > ries,give_up at too many voltage .* give up
> > >
> > drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborti
> > ng 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_ret
> > ries,give_up at too many voltage .* give up
> > >
> > drm:intel_dp_complete_link_train[i915]]*ERROR*failed_to_train_DP,aborti
> > ng 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).
> [He, Shuang] Yes, it seems to happen on same test machine. Is it possible to related to some kernel issue? I see those dmesg warnings happens for almost same set of tests in two rounds of testing on that test machine: igt at pm_rpm*
> 	http://lists.freedesktop.org/archives/intel-gfx/2015-April/064274.html
> 	http://lists.freedesktop.org/archives/intel-gfx/2015-April/064289.html
> while other testing didn't use same hardware seems doesn't have this issue:
> 	http://lists.freedesktop.org/archives/intel-gfx/2015-April/064166.html
> Is it possible it's hardware specific issue?

Well imo the problem here is that PRTS reports something as a regression
which seems to affect all kernels. That's just noise.

Of course the bug itself is still real (and probably a regression), but I
haven't seen a PRTS bisect result for it yet either. Is that stuck
somewhere in the queue?
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch