[Intel-gfx] [igt-dev] [PATCH i-g-t] igt/kms_frontbuffer_tracking: Restore modparams around test

[Chris Wilson]

Quoting Paulo Zanoni (2018-08-06 21:56:15)
> Em Seg, 2018-08-06 às 21:22 +0100, Chris Wilson escreveu:
> > Save the module parameters from setup and restore them on teardown,
> > so
> > that we leave the system in the same state as we found it.
> 
> Currently kms_fbt uses igt_set_module_param_int() which uses
> igt_save_module_param(), which installs an exit handler, which is
> already supposed to accomplish what's described in the sentence above.
> What's missing from the current exit handler? Why is the new strategy
> better?

Hmm, it's clearly not working then as fbc remains enabled after
kms_frontbuffer_tracking:

<7>[ 3305.252856] [IGT] kms_frontbuffer_tracking: exiting, ret=0
<5>[ 3305.252940] Setting dangerous option enable_psr - tainting kernel
<5>[ 3305.253033] Setting dangerous option enable_fbc - tainting kernel
<7>[ 3305.279279] [drm:intel_atomic_check [i915]] [CONNECTOR:67:HDMI-A-1] checking for sink bpp constrains
<7>[ 3305.279317] [drm:intel_hdmi_compute_config [i915]] picking bpc to 12 for HDMI output
<7>[ 3305.279346] [drm:intel_hdmi_compute_config [i915]] forcing pipe bpp to 36 for HDMI
<7>[ 3305.279376] [drm:intel_atomic_check [i915]] hw max bpp: 36, pipe bpp: 36, dithering: 0
<7>[ 3305.279405] [drm:intel_dump_pipe_config [i915]] [CRTC:51:pipe B][modeset]
<7>[ 3305.279434] [drm:intel_dump_pipe_config [i915]] output_types: HDMI (0x40)
<7>[ 3305.279462] [drm:intel_dump_pipe_config [i915]] cpu_transcoder: B, pipe bpp: 36, dithering: 0
<7>[ 3305.279491] [drm:intel_dump_pipe_config [i915]] audio: 1, infoframes: 1
<7>[ 3305.279519] [drm:intel_dump_pipe_config [i915]] requested mode:
<7>[ 3305.279525] [drm:drm_mode_debug_printmodeline] Modeline 0:"1920x1080" 60 148500 1920 2008 2052 2200 1080 1083 1088 1125 0x48 0x9
<7>[ 3305.279555] [drm:intel_dump_pipe_config [i915]] adjusted mode:
<7>[ 3305.279561] [drm:drm_mode_debug_printmodeline] Modeline 0:"1920x1080" 60 148500 1920 2008 2052 2200 1080 1083 1088 1125 0x48 0x9
<7>[ 3305.279592] [drm:intel_dump_pipe_config [i915]] crtc timings: 148500 1920 2008 2052 2200 1080 1083 1088 1125, type: 0x48 flags: 0x9
<7>[ 3305.279621] [drm:intel_dump_pipe_config [i915]] port clock: 222750, pipe src size: 1920x1080, pixel rate 148500
<7>[ 3305.279651] [drm:intel_dump_pipe_config [i915]] pch pfit: pos: 0x00000000, size: 0x00000000, disabled
<7>[ 3305.279680] [drm:intel_dump_pipe_config [i915]] ips: 0, double wide: 0
<7>[ 3305.279708] [drm:intel_dump_pipe_config [i915]] dpll_hw_state: wrpll: 0xb0210414 spll: 0x0
<7>[ 3305.279736] [drm:intel_dump_pipe_config [i915]] planes on this crtc
<7>[ 3305.279764] [drm:intel_dump_pipe_config [i915]] [PLANE:40:primary B] disabled, scaler_id = 0
<7>[ 3305.279793] [drm:intel_dump_pipe_config [i915]] [PLANE:43:sprite B] disabled, scaler_id = 0
<7>[ 3305.279822] [drm:intel_dump_pipe_config [i915]] [PLANE:48:cursor B] disabled, scaler_id = 0
<7>[ 3305.280439] [drm:intel_find_shared_dpll [i915]] [CRTC:51:pipe B] allocated WRPLL 1
<7>[ 3305.280465] [drm:intel_reference_shared_dpll [i915]] using WRPLL 1 for pipe B
<7>[ 3305.280519] [drm:intel_atomic_commit_tail [i915]] [ENCODER:65:CRT]
<7>[ 3305.280544] [drm:intel_atomic_commit_tail [i915]] [ENCODER:66:DDI B]
<7>[ 3305.280570] [drm:intel_atomic_commit_tail [i915]] [ENCODER:73:DDI C]
<7>[ 3305.280595] [drm:intel_atomic_commit_tail [i915]] [ENCODER:76:DDI D]
<7>[ 3305.280620] [drm:intel_atomic_commit_tail [i915]] [ENCODER:78:DP-MST A]
<7>[ 3305.280645] [drm:intel_atomic_commit_tail [i915]] [ENCODER:79:DP-MST B]
<7>[ 3305.280671] [drm:intel_atomic_commit_tail [i915]] [ENCODER:80:DP-MST C]
<7>[ 3305.280696] [drm:verify_single_dpll_state.isra.88 [i915]] WRPLL 1
<7>[ 3305.280722] [drm:verify_single_dpll_state.isra.88 [i915]] WRPLL 2
<7>[ 3305.280747] [drm:verify_single_dpll_state.isra.88 [i915]] SPLL
<7>[ 3305.280773] [drm:verify_single_dpll_state.isra.88 [i915]] LCPLL 810
<7>[ 3305.280798] [drm:verify_single_dpll_state.isra.88 [i915]] LCPLL 1350
<7>[ 3305.280823] [drm:verify_single_dpll_state.isra.88 [i915]] LCPLL 2700
<7>[ 3305.280857] [drm:intel_enable_shared_dpll [i915]] enable WRPLL 1 (active 2, on? 0) for crtc 51
<7>[ 3305.280883] [drm:intel_enable_shared_dpll [i915]] enabling WRPLL 1
<7>[ 3305.280992] [drm:intel_enable_pipe [i915]] enabling pipe B
<7>[ 3305.281048] [drm:intel_audio_codec_enable [i915]] ELD on [CONNECTOR:67:HDMI-A-1], [ENCODER:66:DDI B]
<7>[ 3305.281086] [drm:hsw_audio_codec_enable [i915]] Enable audio codec on pipe B, 32 bytes ELD
<7>[ 3305.281120] [drm:audio_config_hdmi_pixel_clock [i915]] Configuring HDMI audio for pixel clock 148500 (0x00090000)
<7>[ 3305.281146] [drm:hsw_audio_config_update [i915]] using automatic N
<7>[ 3305.319297] [drm:__intel_fbc_disable [i915]] Disabling FBC on pipe A
<7>[ 3305.319328] [drm:verify_connector_state.isra.87 [i915]] [CONNECTOR:67:HDMI-A-1]
<7>[ 3305.319362] [drm:intel_atomic_commit_tail [i915]] [CRTC:51:pipe B]
<7>[ 3305.319396] [drm:verify_single_dpll_state.isra.88 [i915]] WRPLL 1
<7>[ 3305.319794] [drm:intel_fbc_enable [i915]] reserved 11796480 bytes of contiguous stolen space for FBC, threshold: 1
<7>[ 3305.319818] [drm:intel_fbc_enable [i915]] Enabling FBC on pipe A

And that I think makes the difference between rpm working and not.
-Chris