diff mbox series

drm/i915: Steer MCR reads to lowest potential slice/subslice

Message ID 20210611004627.1220031-1-matthew.d.roper@intel.com (mailing list archive)
State New, archived
Headers show
Series drm/i915: Steer MCR reads to lowest potential slice/subslice | expand

Commit Message

Matt Roper June 11, 2021, 12:46 a.m. UTC
When determining the slice/subslice to use for steering multicast
register reads we need to not only consider the fusing (to avoid
steering to a fused off instance), but also the "minconfig" that the
hardware uses to wake from RC6 when render power gating is enabled on
some platforms.  Although it isn't well-documented, certain platforms
(e.g., EHL/JSL) will initially only power up a single instance of
multicast registers when forcewake is grabbed if the GPU isn't actually
busy.  In these cases, only the minconfig slice/subslice will return
valid, non-zero reads so we need to ensure that we steer to the
minconfig specifically.  The minconfig should always be the lowest
slice/subslice that isn't fused off; as such, we should pick our
steering target with ffs() instead of fls() during initialization.

This steering change is especially important on EHL/JSL since there are
cases where the hardware appears to not honor the driver's attempts to
disable render powergating via the POWERGATE_ENABLE (0xA210) register
and will continue to only wake the minconfig's slice/subslice in
response to forcewake.  We can see this in certain reset or
suspend/resume cases where i915 tries to disable render powergating and
then re-applies workarounds before re-enabling powergating; the
workarounds apply successfully, but the readback verification will fail
if we aren't steering to the minconfig register instance.

References: https://gitlab.freedesktop.org/drm/intel/-/issues/1222
Cc: Tejas Upadhyay <tejaskumarx.surendrakumar.upadhyay@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
---
 drivers/gpu/drm/i915/gt/intel_workarounds.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

Comments

Matt Roper June 11, 2021, 11:42 p.m. UTC | #1
On Fri, Jun 11, 2021 at 05:35:53AM +0000, Patchwork wrote:
> == Series Details ==
> 
> Series: drm/i915: Steer MCR reads to lowest potential slice/subslice
> URL   : https://patchwork.freedesktop.org/series/91367/
> State : failure
> 
> == Summary ==
> 
> CI Bug Log - changes from CI_DRM_10206_full -> Patchwork_20340_full
> ====================================================
> 
> Summary
> -------
> 
>   **FAILURE**
> 
>   Serious unknown changes coming with Patchwork_20340_full absolutely need to be
>   verified manually.
>   
>   If you think the reported changes have nothing to do with the changes
>   introduced in Patchwork_20340_full, please notify your bug team to allow them
>   to document this new failure mode, which will reduce false positives in CI.
> 
>   
> 
> Possible new issues
> -------------------
> 
>   Here are the unknown changes that may have been introduced in Patchwork_20340_full:
> 
> ### IGT changes ###
> 
> #### Possible regressions ####
> 
>   * igt@gem_ctx_persistence@legacy-engines-mixed-process@bsd:
>     - shard-iclb:         NOTRUN -> [DMESG-WARN][1]
>    [1]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-iclb6/igt@gem_ctx_persistence@legacy-engines-mixed-process@bsd.html
> 
>   * igt@i915_selftest@perf@engine_cs:
>     - shard-iclb:         [PASS][2] -> [DMESG-WARN][3] +36 similar issues
>    [2]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-iclb8/igt@i915_selftest@perf@engine_cs.html
>    [3]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-iclb7/igt@i915_selftest@perf@engine_cs.html

Steering to the minconfig does seem to have successfully fixed the issue
on EHL/JSL according to the BAT results.  However the code changes
uncovered a similar issue on ICL.  From experimenting on ICL, it appears
that if you don't steer to the minconfig, you can sometimes get random
garbage (rather than 0's) when render power gating is enabled.  CI
wasn't flagging a workaround warning on ICL all along only because we
were reading back random garbage that just happened to have a '1' in the
relevant bit.

So the problem now is that the fls() -> ffs() conversion didn't actually
get us to the minconfig on this ICL system.  Since there are two types
of multicast registers on gen11 (subslice multicast and l3bank
multicast), we currently pick our subslice target by &'ing those two
masks together.  Unfortunately the minconfig subslice may not also be a
suitable l3bank, so even using ffs() instead of fls() on the
intersection will give us a "bad" steering ID.

It looks like there will be cases where we can't just always use the
same steering value for both the subslice multicast registers and the
l3bank multicast registers; we'll probably want to steer to the
minconfig subslice by default and then explicitly re-steer to a valid
l3bank in cases where we can't find a suitable value for both.  I
already have some patches that do something similar for steering on
upcoming platforms, so I'll get those reorganized so that we can use
them on these platforms as well.


Matt

> 
>   * igt@kms_draw_crc@draw-method-rgb565-mmap-wc-untiled:
>     - shard-glk:          [PASS][4] -> [FAIL][5]
>    [4]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-glk1/igt@kms_draw_crc@draw-method-rgb565-mmap-wc-untiled.html
>    [5]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-glk8/igt@kms_draw_crc@draw-method-rgb565-mmap-wc-untiled.html
> 
>   
> Known issues
> ------------
> 
>   Here are the changes found in Patchwork_20340_full that come from known issues:
> 
> ### IGT changes ###
> 
> #### Issues hit ####
> 
>   * igt@gem_create@create-massive:
>     - shard-snb:          NOTRUN -> [DMESG-WARN][6] ([i915#3002])
>    [6]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-snb5/igt@gem_create@create-massive.html
> 
>   * igt@gem_ctx_persistence@legacy-engines-queued:
>     - shard-snb:          NOTRUN -> [SKIP][7] ([fdo#109271] / [i915#1099]) +6 similar issues
>    [7]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-snb5/igt@gem_ctx_persistence@legacy-engines-queued.html
> 
>   * igt@gem_ctx_persistence@many-contexts:
>     - shard-tglb:         [PASS][8] -> [FAIL][9] ([i915#2410])
>    [8]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-tglb3/igt@gem_ctx_persistence@many-contexts.html
>    [9]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-tglb2/igt@gem_ctx_persistence@many-contexts.html
> 
>   * igt@gem_eio@in-flight-contexts-10ms:
>     - shard-tglb:         [PASS][10] -> [TIMEOUT][11] ([i915#3063])
>    [10]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-tglb1/igt@gem_eio@in-flight-contexts-10ms.html
>    [11]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-tglb5/igt@gem_eio@in-flight-contexts-10ms.html
> 
>   * igt@gem_exec_fair@basic-flow@rcs0:
>     - shard-tglb:         [PASS][12] -> [FAIL][13] ([i915#2842])
>    [12]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-tglb6/igt@gem_exec_fair@basic-flow@rcs0.html
>    [13]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-tglb7/igt@gem_exec_fair@basic-flow@rcs0.html
> 
>   * igt@gem_exec_fair@basic-none-solo@rcs0:
>     - shard-glk:          [PASS][14] -> [FAIL][15] ([i915#2842]) +3 similar issues
>    [14]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-glk5/igt@gem_exec_fair@basic-none-solo@rcs0.html
>    [15]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-glk2/igt@gem_exec_fair@basic-none-solo@rcs0.html
> 
>   * igt@gem_exec_fair@basic-pace-solo@rcs0:
>     - shard-kbl:          [PASS][16] -> [FAIL][17] ([i915#2842]) +1 similar issue
>    [16]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-kbl2/igt@gem_exec_fair@basic-pace-solo@rcs0.html
>    [17]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-kbl6/igt@gem_exec_fair@basic-pace-solo@rcs0.html
> 
>   * igt@gem_mmap_gtt@big-copy:
>     - shard-glk:          [PASS][18] -> [FAIL][19] ([i915#307]) +1 similar issue
>    [18]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-glk2/igt@gem_mmap_gtt@big-copy.html
>    [19]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-glk3/igt@gem_mmap_gtt@big-copy.html
> 
>   * igt@gem_mmap_gtt@cpuset-big-copy-odd:
>     - shard-iclb:         [PASS][20] -> [FAIL][21] ([i915#307]) +2 similar issues
>    [20]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-iclb6/igt@gem_mmap_gtt@cpuset-big-copy-odd.html
>    [21]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-iclb3/igt@gem_mmap_gtt@cpuset-big-copy-odd.html
> 
>   * igt@gem_pread@exhaustion:
>     - shard-snb:          NOTRUN -> [WARN][22] ([i915#2658])
>    [22]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-snb5/igt@gem_pread@exhaustion.html
>     - shard-kbl:          NOTRUN -> [WARN][23] ([i915#2658])
>    [23]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-kbl4/igt@gem_pread@exhaustion.html
> 
>   * igt@gem_userptr_blits@vma-merge:
>     - shard-snb:          NOTRUN -> [FAIL][24] ([i915#2724])
>    [24]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-snb5/igt@gem_userptr_blits@vma-merge.html
>     - shard-apl:          NOTRUN -> [FAIL][25] ([i915#3318])
>    [25]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-apl8/igt@gem_userptr_blits@vma-merge.html
> 
>   * igt@gen3_mixed_blits:
>     - shard-tglb:         NOTRUN -> [SKIP][26] ([fdo#109289]) +1 similar issue
>    [26]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-tglb3/igt@gen3_mixed_blits.html
> 
>   * igt@gen9_exec_parse@basic-rejected-ctx-param:
>     - shard-tglb:         NOTRUN -> [SKIP][27] ([fdo#112306])
>    [27]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-tglb3/igt@gen9_exec_parse@basic-rejected-ctx-param.html
> 
>   * igt@gen9_exec_parse@bb-large:
>     - shard-apl:          NOTRUN -> [FAIL][28] ([i915#3296])
>    [28]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-apl8/igt@gen9_exec_parse@bb-large.html
> 
>   * igt@i915_pm_dc@dc6-psr:
>     - shard-skl:          [PASS][29] -> [FAIL][30] ([i915#454])
>    [29]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-skl9/igt@i915_pm_dc@dc6-psr.html
>    [30]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-skl3/igt@i915_pm_dc@dc6-psr.html
> 
>   * igt@i915_pm_rpm@modeset-non-lpsp-stress-no-wait:
>     - shard-tglb:         NOTRUN -> [SKIP][31] ([fdo#111644] / [i915#1397] / [i915#2411])
>    [31]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-tglb3/igt@i915_pm_rpm@modeset-non-lpsp-stress-no-wait.html
> 
>   * igt@i915_suspend@forcewake:
>     - shard-apl:          NOTRUN -> [DMESG-WARN][32] ([i915#180])
>    [32]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-apl3/igt@i915_suspend@forcewake.html
> 
>   * igt@kms_big_fb@x-tiled-64bpp-rotate-270:
>     - shard-tglb:         NOTRUN -> [SKIP][33] ([fdo#111614])
>    [33]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-tglb3/igt@kms_big_fb@x-tiled-64bpp-rotate-270.html
> 
>   * igt@kms_big_fb@yf-tiled-32bpp-rotate-180:
>     - shard-tglb:         NOTRUN -> [SKIP][34] ([fdo#111615])
>    [34]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-tglb3/igt@kms_big_fb@yf-tiled-32bpp-rotate-180.html
> 
>   * igt@kms_ccs@pipe-c-crc-sprite-planes-basic:
>     - shard-tglb:         [PASS][35] -> [DMESG-WARN][36] ([i915#2868]) +1 similar issue
>    [35]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-tglb1/igt@kms_ccs@pipe-c-crc-sprite-planes-basic.html
>    [36]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-tglb5/igt@kms_ccs@pipe-c-crc-sprite-planes-basic.html
> 
>   * igt@kms_chamelium@dp-mode-timings:
>     - shard-apl:          NOTRUN -> [SKIP][37] ([fdo#109271] / [fdo#111827]) +16 similar issues
>    [37]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-apl6/igt@kms_chamelium@dp-mode-timings.html
> 
>   * igt@kms_chamelium@hdmi-aspect-ratio:
>     - shard-skl:          NOTRUN -> [SKIP][38] ([fdo#109271] / [fdo#111827]) +5 similar issues
>    [38]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-skl5/igt@kms_chamelium@hdmi-aspect-ratio.html
> 
>   * igt@kms_chamelium@hdmi-edid-read:
>     - shard-tglb:         NOTRUN -> [SKIP][39] ([fdo#109284] / [fdo#111827]) +2 similar issues
>    [39]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-tglb3/igt@kms_chamelium@hdmi-edid-read.html
> 
>   * igt@kms_chamelium@hdmi-hpd-with-enabled-mode:
>     - shard-snb:          NOTRUN -> [SKIP][40] ([fdo#109271] / [fdo#111827]) +21 similar issues
>    [40]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-snb7/igt@kms_chamelium@hdmi-hpd-with-enabled-mode.html
> 
>   * igt@kms_chamelium@vga-hpd-for-each-pipe:
>     - shard-kbl:          NOTRUN -> [SKIP][41] ([fdo#109271] / [fdo#111827]) +5 similar issues
>    [41]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-kbl4/igt@kms_chamelium@vga-hpd-for-each-pipe.html
> 
>   * igt@kms_color_chamelium@pipe-b-degamma:
>     - shard-glk:          NOTRUN -> [SKIP][42] ([fdo#109271] / [fdo#111827])
>    [42]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-glk6/igt@kms_color_chamelium@pipe-b-degamma.html
> 
>   * igt@kms_content_protection@mei_interface:
>     - shard-tglb:         NOTRUN -> [SKIP][43] ([fdo#111828])
>    [43]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-tglb3/igt@kms_content_protection@mei_interface.html
> 
>   * igt@kms_cursor_crc@pipe-a-cursor-512x170-random:
>     - shard-tglb:         NOTRUN -> [SKIP][44] ([fdo#109279] / [i915#3359]) +1 similar issue
>    [44]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-tglb3/igt@kms_cursor_crc@pipe-a-cursor-512x170-random.html
> 
>   * igt@kms_cursor_crc@pipe-c-cursor-32x32-sliding:
>     - shard-tglb:         NOTRUN -> [SKIP][45] ([i915#3319]) +1 similar issue
>    [45]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-tglb3/igt@kms_cursor_crc@pipe-c-cursor-32x32-sliding.html
> 
>   * igt@kms_cursor_legacy@pipe-d-single-bo:
>     - shard-apl:          NOTRUN -> [SKIP][46] ([fdo#109271] / [i915#533])
>    [46]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-apl7/igt@kms_cursor_legacy@pipe-d-single-bo.html
> 
>   * igt@kms_dp_tiled_display@basic-test-pattern-with-chamelium:
>     - shard-tglb:         NOTRUN -> [SKIP][47] ([i915#3528])
>    [47]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-tglb3/igt@kms_dp_tiled_display@basic-test-pattern-with-chamelium.html
> 
>   * igt@kms_flip@absolute-wf_vblank-interruptible@a-edp1:
>     - shard-skl:          [PASS][48] -> [DMESG-WARN][49] ([i915#1982]) +1 similar issue
>    [48]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-skl5/igt@kms_flip@absolute-wf_vblank-interruptible@a-edp1.html
>    [49]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-skl4/igt@kms_flip@absolute-wf_vblank-interruptible@a-edp1.html
> 
>   * igt@kms_flip@flip-vs-suspend@c-dp1:
>     - shard-kbl:          [PASS][50] -> [DMESG-WARN][51] ([i915#180]) +2 similar issues
>    [50]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-kbl4/igt@kms_flip@flip-vs-suspend@c-dp1.html
>    [51]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-kbl3/igt@kms_flip@flip-vs-suspend@c-dp1.html
> 
>   * igt@kms_flip_scaled_crc@flip-64bpp-ytile-to-32bpp-ytilercccs:
>     - shard-kbl:          NOTRUN -> [SKIP][52] ([fdo#109271] / [i915#2672])
>    [52]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-kbl4/igt@kms_flip_scaled_crc@flip-64bpp-ytile-to-32bpp-ytilercccs.html
> 
>   * igt@kms_frontbuffer_tracking@fbcpsr-1p-primscrn-indfb-msflip-blt:
>     - shard-skl:          NOTRUN -> [SKIP][53] ([fdo#109271]) +96 similar issues
>    [53]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-skl4/igt@kms_frontbuffer_tracking@fbcpsr-1p-primscrn-indfb-msflip-blt.html
> 
>   * igt@kms_frontbuffer_tracking@fbcpsr-2p-primscrn-pri-indfb-draw-render:
>     - shard-tglb:         NOTRUN -> [SKIP][54] ([fdo#111825]) +8 similar issues
>    [54]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-tglb3/igt@kms_frontbuffer_tracking@fbcpsr-2p-primscrn-pri-indfb-draw-render.html
> 
>   * igt@kms_hdr@bpc-switch-suspend:
>     - shard-skl:          [PASS][55] -> [FAIL][56] ([i915#1188])
>    [55]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-skl1/igt@kms_hdr@bpc-switch-suspend.html
>    [56]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-skl1/igt@kms_hdr@bpc-switch-suspend.html
> 
>   * igt@kms_pipe_crc_basic@suspend-read-crc-pipe-d:
>     - shard-glk:          NOTRUN -> [SKIP][57] ([fdo#109271] / [i915#533])
>    [57]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-glk6/igt@kms_pipe_crc_basic@suspend-read-crc-pipe-d.html
> 
>   * igt@kms_plane_alpha_blend@pipe-b-alpha-basic:
>     - shard-apl:          NOTRUN -> [FAIL][58] ([fdo#108145] / [i915#265]) +1 similar issue
>    [58]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-apl8/igt@kms_plane_alpha_blend@pipe-b-alpha-basic.html
> 
>   * igt@kms_plane_alpha_blend@pipe-b-coverage-7efc:
>     - shard-skl:          [PASS][59] -> [FAIL][60] ([fdo#108145] / [i915#265]) +1 similar issue
>    [59]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-skl5/igt@kms_plane_alpha_blend@pipe-b-coverage-7efc.html
>    [60]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-skl10/igt@kms_plane_alpha_blend@pipe-b-coverage-7efc.html
> 
>   * igt@kms_plane_alpha_blend@pipe-c-coverage-7efc:
>     - shard-skl:          NOTRUN -> [FAIL][61] ([fdo#108145] / [i915#265]) +1 similar issue
>    [61]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-skl6/igt@kms_plane_alpha_blend@pipe-c-coverage-7efc.html
> 
>   * igt@kms_psr2_sf@cursor-plane-update-sf:
>     - shard-kbl:          NOTRUN -> [SKIP][62] ([fdo#109271] / [i915#658])
>    [62]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-kbl4/igt@kms_psr2_sf@cursor-plane-update-sf.html
> 
>   * igt@kms_psr2_sf@overlay-plane-update-sf-dmg-area-3:
>     - shard-apl:          NOTRUN -> [SKIP][63] ([fdo#109271] / [i915#658]) +3 similar issues
>    [63]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-apl8/igt@kms_psr2_sf@overlay-plane-update-sf-dmg-area-3.html
> 
>   * igt@kms_psr2_sf@overlay-primary-update-sf-dmg-area-1:
>     - shard-glk:          NOTRUN -> [SKIP][64] ([fdo#109271] / [i915#658]) +1 similar issue
>    [64]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-glk6/igt@kms_psr2_sf@overlay-primary-update-sf-dmg-area-1.html
> 
>   * igt@kms_psr@psr2_cursor_mmap_cpu:
>     - shard-iclb:         [PASS][65] -> [SKIP][66] ([fdo#109441]) +3 similar issues
>    [65]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-iclb2/igt@kms_psr@psr2_cursor_mmap_cpu.html
>    [66]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-iclb6/igt@kms_psr@psr2_cursor_mmap_cpu.html
> 
>   * igt@kms_psr@psr2_cursor_plane_move:
>     - shard-tglb:         NOTRUN -> [FAIL][67] ([i915#132] / [i915#3467])
>    [67]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-tglb3/igt@kms_psr@psr2_cursor_plane_move.html
> 
>   * igt@kms_universal_plane@disable-primary-vs-flip-pipe-d:
>     - shard-kbl:          NOTRUN -> [SKIP][68] ([fdo#109271]) +69 similar issues
>    [68]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-kbl4/igt@kms_universal_plane@disable-primary-vs-flip-pipe-d.html
>     - shard-snb:          NOTRUN -> [SKIP][69] ([fdo#109271]) +386 similar issues
>    [69]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-snb5/igt@kms_universal_plane@disable-primary-vs-flip-pipe-d.html
> 
>   * igt@kms_vblank@pipe-d-ts-continuation-idle:
>     - shard-apl:          NOTRUN -> [SKIP][70] ([fdo#109271]) +128 similar issues
>    [70]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-apl6/igt@kms_vblank@pipe-d-ts-continuation-idle.html
> 
>   * igt@nouveau_crc@pipe-a-source-outp-inactive:
>     - shard-tglb:         NOTRUN -> [SKIP][71] ([i915#2530])
>    [71]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-tglb3/igt@nouveau_crc@pipe-a-source-outp-inactive.html
> 
>   * igt@nouveau_crc@pipe-b-source-outp-complete:
>     - shard-glk:          NOTRUN -> [SKIP][72] ([fdo#109271]) +12 similar issues
>    [72]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-glk6/igt@nouveau_crc@pipe-b-source-outp-complete.html
> 
>   * igt@perf_pmu@module-unload:
>     - shard-iclb:         [PASS][73] -> [DMESG-WARN][74] ([i915#262])
>    [73]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-iclb5/igt@perf_pmu@module-unload.html
>    [74]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-iclb7/igt@perf_pmu@module-unload.html
> 
>   * igt@prime_nv_pcopy@test1_macro:
>     - shard-tglb:         NOTRUN -> [SKIP][75] ([fdo#109291])
>    [75]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-tglb3/igt@prime_nv_pcopy@test1_macro.html
> 
>   * igt@sysfs_clients@create:
>     - shard-skl:          NOTRUN -> [SKIP][76] ([fdo#109271] / [i915#2994])
>    [76]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-skl6/igt@sysfs_clients@create.html
> 
>   * igt@sysfs_clients@recycle-many:
>     - shard-glk:          NOTRUN -> [SKIP][77] ([fdo#109271] / [i915#2994])
>    [77]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-glk6/igt@sysfs_clients@recycle-many.html
> 
>   * igt@sysfs_clients@split-10:
>     - shard-tglb:         NOTRUN -> [SKIP][78] ([i915#2994])
>    [78]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-tglb3/igt@sysfs_clients@split-10.html
> 
>   * igt@sysfs_clients@split-25:
>     - shard-apl:          NOTRUN -> [SKIP][79] ([fdo#109271] / [i915#2994]) +1 similar issue
>    [79]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-apl1/igt@sysfs_clients@split-25.html
> 
>   
> #### Possible fixes ####
> 
>   * igt@feature_discovery@psr2:
>     - shard-iclb:         [SKIP][80] ([i915#658]) -> [PASS][81]
>    [80]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-iclb8/igt@feature_discovery@psr2.html
>    [81]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-iclb2/igt@feature_discovery@psr2.html
> 
>   * igt@gem_eio@in-flight-internal-10ms:
>     - shard-tglb:         [DMESG-WARN][82] ([i915#2868]) -> [PASS][83] +3 similar issues
>    [82]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-tglb5/igt@gem_eio@in-flight-internal-10ms.html
>    [83]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-tglb8/igt@gem_eio@in-flight-internal-10ms.html
> 
>   * igt@gem_exec_fair@basic-deadline:
>     - shard-glk:          [FAIL][84] ([i915#2846]) -> [PASS][85]
>    [84]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-glk6/igt@gem_exec_fair@basic-deadline.html
>    [85]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-glk9/igt@gem_exec_fair@basic-deadline.html
> 
>   * igt@gem_exec_fair@basic-none@vcs0:
>     - shard-kbl:          [FAIL][86] ([i915#2842]) -> [PASS][87]
>    [86]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-kbl4/igt@gem_exec_fair@basic-none@vcs0.html
>    [87]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-kbl4/igt@gem_exec_fair@basic-none@vcs0.html
> 
>   * igt@gem_exec_whisper@basic-fds-forked:
>     - shard-glk:          [DMESG-WARN][88] ([i915#118] / [i915#95]) -> [PASS][89]
>    [88]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-glk3/igt@gem_exec_whisper@basic-fds-forked.html
>    [89]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-glk3/igt@gem_exec_whisper@basic-fds-forked.html
> 
>   * igt@gem_mmap_gtt@big-copy-xy:
>     - shard-skl:          [FAIL][90] ([i915#307]) -> [PASS][91]
>    [90]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-skl8/igt@gem_mmap_gtt@big-copy-xy.html
>    [91]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-skl10/igt@gem_mmap_gtt@big-copy-xy.html
> 
>   * igt@gem_mmap_offset@clear:
>     - shard-glk:          [FAIL][92] ([i915#1888] / [i915#3160]) -> [PASS][93]
>    [92]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-glk2/igt@gem_mmap_offset@clear.html
>    [93]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-glk8/igt@gem_mmap_offset@clear.html
> 
>   * igt@gem_workarounds@suspend-resume-context:
>     - shard-apl:          [DMESG-WARN][94] ([i915#180]) -> [PASS][95] +1 similar issue
>    [94]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-apl3/igt@gem_workarounds@suspend-resume-context.html
>    [95]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-apl7/igt@gem_workarounds@suspend-resume-context.html
> 
>   * igt@gen9_exec_parse@allowed-single:
>     - shard-skl:          [DMESG-WARN][96] ([i915#1436] / [i915#716]) -> [PASS][97]
>    [96]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-skl6/igt@gen9_exec_parse@allowed-single.html
>    [97]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-skl4/igt@gen9_exec_parse@allowed-single.html
> 
>   * igt@kms_async_flips@alternate-sync-async-flip:
>     - shard-skl:          [FAIL][98] ([i915#2521]) -> [PASS][99]
>    [98]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-skl1/igt@kms_async_flips@alternate-sync-async-flip.html
>    [99]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-skl6/igt@kms_async_flips@alternate-sync-async-flip.html
> 
>   * igt@kms_cursor_legacy@flip-vs-cursor-varying-size:
>     - shard-skl:          [FAIL][100] ([i915#2346]) -> [PASS][101]
>    [100]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-skl4/igt@kms_cursor_legacy@flip-vs-cursor-varying-size.html
>    [101]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-skl8/igt@kms_cursor_legacy@flip-vs-cursor-varying-size.html
> 
>   * igt@kms_draw_crc@draw-method-rgb565-blt-ytiled:
>     - shard-skl:          [FAIL][102] -> [PASS][103] +1 similar issue
>    [102]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-skl9/igt@kms_draw_crc@draw-method-rgb565-blt-ytiled.html
>    [103]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-skl8/igt@kms_draw_crc@draw-method-rgb565-blt-ytiled.html
> 
>   * igt@kms_draw_crc@draw-method-xrgb2101010-blt-untiled:
>     - shard-skl:          [DMESG-WARN][104] ([i915#1982]) -> [PASS][105]
>    [104]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-skl9/igt@kms_draw_crc@draw-method-xrgb2101010-blt-untiled.html
>    [105]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-skl7/igt@kms_draw_crc@draw-method-xrgb2101010-blt-untiled.html
> 
>   * igt@kms_fbcon_fbt@psr-suspend:
>     - shard-skl:          [INCOMPLETE][106] ([i915#146] / [i915#198]) -> [PASS][107]
>    [106]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-skl1/igt@kms_fbcon_fbt@psr-suspend.html
>    [107]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-skl6/igt@kms_fbcon_fbt@psr-suspend.html
> 
>   * igt@kms_flip@2x-flip-vs-expired-vblank-interruptible@bc-hdmi-a1-hdmi-a2:
>     - shard-glk:          [FAIL][108] ([i915#79]) -> [PASS][109]
>    [108]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-glk8/igt@kms_flip@2x-flip-vs-expired-vblank-interruptible@bc-hdmi-a1-hdmi-a2.html
>    [109]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-glk4/igt@kms_flip@2x-flip-vs-expired-vblank-interruptible@bc-hdmi-a1-hdmi-a2.html
> 
>   * igt@kms_flip@2x-flip-vs-suspend@ab-hdmi-a1-hdmi-a2:
>     - shard-glk:          [INCOMPLETE][110] -> [PASS][111]
>    [110]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-glk4/igt@kms_flip@2x-flip-vs-suspend@ab-hdmi-a1-hdmi-a2.html
>    [111]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-glk6/igt@kms_flip@2x-flip-vs-suspend@ab-hdmi-a1-hdmi-a2.html
> 
>   * igt@kms_flip@flip-vs-suspend-interruptible@c-edp1:
>     - shard-skl:          [INCOMPLETE][112] ([i915#198]) -> [PASS][113]
>    [112]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-skl10/igt@kms_flip@flip-vs-suspend-interruptible@c-edp1.html
>    [113]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-skl5/igt@kms_flip@flip-vs-suspend-interruptible@c-edp1.html
> 
>   * igt@kms_flip@plain-flip-ts-check-interruptible@c-edp1:
>     - shard-skl:          [FAIL][114] ([i915#2122]) -> [PASS][115]
>    [114]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-skl8/igt@kms_flip@plain-flip-ts-check-interruptible@c-edp1.html
>    [115]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-skl10/igt@kms_flip@plain-flip-ts-check-interruptible@c-edp1.html
> 
>   * igt@kms_hdr@bpc-switch-suspend:
>     - shard-kbl:          [DMESG-WARN][116] ([i915#180]) -> [PASS][117] +5 similar issues
>    [116]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-kbl1/igt@kms_hdr@bpc-switch-suspend.html
>    [117]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-kbl4/igt@kms_hdr@bpc-switch-suspend.html
> 
>   * igt@kms_plane_alpha_blend@pipe-a-constant-alpha-min:
>     - shard-skl:          [FAIL][118] ([fdo#108145] / [i915#265]) -> [PASS][119]
>    [118]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-skl9/igt@kms_plane_alpha_blend@pipe-a-constant-alpha-min.html
>    [119]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-skl8/igt@kms_plane_alpha_blend@pipe-a-constant-alpha-min.html
> 
>   * igt@kms_psr@psr2_suspend:
>     - shard-iclb:         [SKIP][120] ([fdo#109441]) -> [PASS][121] +1 similar issue
>    [120]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-iclb8/igt@kms_psr@psr2_suspend.html
>    [121]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-iclb2/igt@kms_psr@psr2_suspend.html
> 
>   * igt@kms_vblank@pipe-c-ts-continuation-dpms-suspend:
>     - shard-tglb:         [INCOMPLETE][122] ([i915#456]) -> [PASS][123]
>    [122]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-tglb1/igt@kms_vblank@pipe-c-ts-continuation-dpms-suspend.html
>    [123]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-tglb3/igt@kms_vblank@pipe-c-ts-continuation-dpms-suspend.html
> 
>   * igt@kms_vblank@pipe-d-ts-continuation-dpms-suspend:
>     - shard-tglb:         [DMESG-WARN][124] ([i915#2411] / [i915#2868]) -> [PASS][125]
>    [124]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-tglb5/igt@kms_vblank@pipe-d-ts-continuation-dpms-suspend.html
>    [125]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-tglb8/igt@kms_vblank@pipe-d-ts-continuation-dpms-suspend.html
> 
>   * igt@perf@polling-parameterized:
>     - shard-iclb:         [FAIL][126] ([i915#1542]) -> [PASS][127]
>    [126]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-iclb1/igt@perf@polling-parameterized.html
>    [127]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-iclb6/igt@perf@polling-parameterized.html
> 
>   
> #### Warnings ####
> 
>   * igt@gem_exec_fair@basic-throttle@rcs0:
>     - shard-iclb:         [FAIL][128] ([i915#2842]) -> [FAIL][129] ([i915#2849])
>    [128]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-iclb4/igt@gem_exec_fair@basic-throttle@rcs0.html
>    [129]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-iclb4/igt@gem_exec_fair@basic-throttle@rcs0.html
> 
>   * igt@i915_pm_rc6_residency@rc6-fence:
>     - shard-iclb:         [WARN][130] ([i915#1804] / [i915#2684]) -> [WARN][131] ([i915#2684]) +1 similar issue
>    [130]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-iclb4/igt@i915_pm_rc6_residency@rc6-fence.html
>    [131]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-iclb8/igt@i915_pm_rc6_residency@rc6-fence.html
> 
>   * igt@i915_selftest@live@execlists:
>     - shard-skl:          [INCOMPLETE][132] -> [INCOMPLETE][133] ([i915#2782] / [i915#3462])
>    [132]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-skl7/igt@i915_selftest@live@execlists.html
>    [133]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-skl4/igt@i915_selftest@live@execlists.html
>     - shard-iclb:         [INCOMPLETE][134] ([i915#2782] / [i915#3462]) -> [DMESG-FAIL][135] ([i915#3462])
>    [134]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-iclb1/igt@i915_selftest@live@execlists.html
>    [135]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-iclb5/igt@i915_selftest@live@execlists.html
> 
>   * igt@kms_psr2_sf@cursor-plane-update-sf:
>     - shard-iclb:         [SKIP][136] ([i915#2920]) -> [SKIP][137] ([i915#658])
>    [136]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-iclb2/igt@kms_psr2_sf@cursor-plane-update-sf.html
>    [137]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-iclb5/igt@kms_psr2_sf@cursor-plane-update-sf.html
> 
>   * igt@kms_psr2_sf@primary-plane-update-sf-dmg-area-1:
>     - shard-iclb:         [SKIP][138] ([i915#658]) -> [SKIP][139] ([i915#2920]) +2 similar issues
>    [138]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-iclb3/igt@kms_psr2_sf@primary-plane-update-sf-dmg-area-1.html
>    [139]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-iclb2/igt@kms_psr2_sf@primary-plane-update-sf-dmg-area-1.html
> 
>   * igt@runner@aborted:
>     - shard-kbl:          ([FAIL][140], [FAIL][141], [FAIL][142], [FAIL][143], [FAIL][144], [FAIL][145], [FAIL][146], [FAIL][147], [FAIL][148], [FAIL][149]) ([i915#1436] / [i915#180] / [i915#1814] / [i915#2505] / [i915#3002] / [i915#3363] / [i915#92]) -> ([FAIL][150], [FAIL][151], [FAIL][152], [FAIL][153], [FAIL][154], [FAIL][155]) ([i915#1436] / [i915#180] / [i915#1814] / [i915#3002] / [i915#3363] / [i915#92])
>    [140]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-kbl3/igt@runner@aborted.html
>    [141]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-kbl1/igt@runner@aborted.html
>    [142]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-kbl1/igt@runner@aborted.html
>    [143]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-kbl6/igt@runner@aborted.html
>    [144]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-kbl7/igt@runner@aborted.html
>    [145]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-kbl6/igt@runner@aborted.html
>    [
> 
> == Logs ==
> 
> For more details see: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/index.html
Tvrtko Ursulin June 14, 2021, 8:48 a.m. UTC | #2
On 12/06/2021 00:42, Matt Roper wrote:
> On Fri, Jun 11, 2021 at 05:35:53AM +0000, Patchwork wrote:
>> == Series Details ==
>>
>> Series: drm/i915: Steer MCR reads to lowest potential slice/subslice
>> URL   : https://patchwork.freedesktop.org/series/91367/
>> State : failure
>>
>> == Summary ==
>>
>> CI Bug Log - changes from CI_DRM_10206_full -> Patchwork_20340_full
>> ====================================================
>>
>> Summary
>> -------
>>
>>    **FAILURE**
>>
>>    Serious unknown changes coming with Patchwork_20340_full absolutely need to be
>>    verified manually.
>>    
>>    If you think the reported changes have nothing to do with the changes
>>    introduced in Patchwork_20340_full, please notify your bug team to allow them
>>    to document this new failure mode, which will reduce false positives in CI.
>>
>>    
>>
>> Possible new issues
>> -------------------
>>
>>    Here are the unknown changes that may have been introduced in Patchwork_20340_full:
>>
>> ### IGT changes ###
>>
>> #### Possible regressions ####
>>
>>    * igt@gem_ctx_persistence@legacy-engines-mixed-process@bsd:
>>      - shard-iclb:         NOTRUN -> [DMESG-WARN][1]
>>     [1]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-iclb6/igt@gem_ctx_persistence@legacy-engines-mixed-process@bsd.html
>>
>>    * igt@i915_selftest@perf@engine_cs:
>>      - shard-iclb:         [PASS][2] -> [DMESG-WARN][3] +36 similar issues
>>     [2]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10206/shard-iclb8/igt@i915_selftest@perf@engine_cs.html
>>     [3]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20340/shard-iclb7/igt@i915_selftest@perf@engine_cs.html
> 
> Steering to the minconfig does seem to have successfully fixed the issue
> on EHL/JSL according to the BAT results.  However the code changes
> uncovered a similar issue on ICL.  From experimenting on ICL, it appears
> that if you don't steer to the minconfig, you can sometimes get random
> garbage (rather than 0's) when render power gating is enabled.  CI
> wasn't flagging a workaround warning on ICL all along only because we
> were reading back random garbage that just happened to have a '1' in the
> relevant bit.
> 
> So the problem now is that the fls() -> ffs() conversion didn't actually
> get us to the minconfig on this ICL system.  Since there are two types
> of multicast registers on gen11 (subslice multicast and l3bank
> multicast), we currently pick our subslice target by &'ing those two
> masks together.  Unfortunately the minconfig subslice may not also be a
> suitable l3bank, so even using ffs() instead of fls() on the
> intersection will give us a "bad" steering ID.
> 
> It looks like there will be cases where we can't just always use the
> same steering value for both the subslice multicast registers and the
> l3bank multicast registers; we'll probably want to steer to the
> minconfig subslice by default and then explicitly re-steer to a valid
> l3bank in cases where we can't find a suitable value for both.  I
> already have some patches that do something similar for steering on
> upcoming platforms, so I'll get those reorganized so that we can use
> them on these platforms as well.

Kudos for figuring this all out! This until now unexplained fls vs ffs 
issue has been annoying us for years.

Regards,

Tvrtko
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds.c b/drivers/gpu/drm/i915/gt/intel_workarounds.c
index b62d1e31a645..0c973678bf03 100644
--- a/drivers/gpu/drm/i915/gt/intel_workarounds.c
+++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c
@@ -991,13 +991,13 @@  wa_init_mcr(struct drm_i915_private *i915, struct i915_wa_list *wal)
 		l3_en = ~0;
 	}
 
-	slice = fls(sseu->slice_mask) - 1;
-	subslice = fls(l3_en & intel_sseu_get_subslices(sseu, slice));
+	slice = ffs(sseu->slice_mask) - 1;
+	subslice = ffs(l3_en & intel_sseu_get_subslices(sseu, slice));
 	if (!subslice) {
 		drm_warn(&i915->drm,
 			 "No common index found between subslice mask %x and L3 bank mask %x!\n",
 			 intel_sseu_get_subslices(sseu, slice), l3_en);
-		subslice = fls(l3_en);
+		subslice = ffs(l3_en);
 		drm_WARN_ON(&i915->drm, !subslice);
 	}
 	subslice--;