drm/i915/debugfs: switch crtc debugfs to struct intel_crtc

Convert the crtc debugfs code to use struct intel_crtc instead of struct
drm_crtc.

v2: Fix build for CONFIG_DRM_I915_DEBUG_VBLANK_EVADE=y (kernel test robot)

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230320124429.786985-1-jani.nikula@intel.com

drm/i915/debugfs: pass intel_connector to intel_connector_debugfs_add()

Prefer the intel_ types. No functional changes.

v2: Fix build.

Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210830140222.12228-1-jani.nikula@intel.com

drm/i915/display: stop returning errors from debugfs registration

Failures to register debugfs should be ignored anyway, so stop
propagating errors altogether for clarity and simplicity. No functional
changes.

Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/346562ccef2282ccdbdea54409fab1d2b48f313c.1630327990.git.jani.nikula@intel.com

drm/i915/display: Record the plane update times for debugging

Since we try and estimate how long we require to update the registers to
perform a plane update, it is of vital importance that we measure the
distribution of plane updates to better guide our estimate. If we
underestimate how long it takes to perform the plane update, we may
slip into the next scanout frame causing a tear. If we overestimate, we
may unnecessarily delay the update to the next frame, causing visible
jitter.

Replace the warning that we exceed some arbitrary threshold for the
vblank update with a histogram for debugfs.

v2: Add a per-crtc debugfs entry so that the information is easier to
extract when testing individual CRTC, and so that it can be reset before
a test.

v3: Flip the graph on its side; creates space to label the time axis.

Updates: 4684
|
1us |
|
4us |********
|**********
16us |***********
|*****
66us |
|
262us |
|
1ms |
|
4ms |
|
17ms |
|
Min update: 5918ns
Max update: 54781ns
Average update: 16628ns
Overruns > 250us: 0

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/1982
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> #v2
Link: https://patchwork.freedesktop.org/patch/msgid/20201202212814.26320-1-chris@chris-wilson.co.uk

drm/i915: have *_debugfs_init() functions return void.

Since commit 987d65d01356 (drm: debugfs: make
drm_debugfs_create_files() never fail), drm_debugfs_create_files() never
fails and should return void. Therefore, remove its use as the
return value of debugfs_init() functions and have the functions return
void.

v2: convert intel_display_debugfs_register() stub to return void too.

Signed-off-by: Wambui Karuga <wambui.karugax@gmail.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200310133121.27913-15-wambui.karugax@gmail.com

drm/i915: split out display debugfs to a separate file

The i915_debugfs.c has grown more than a little unwieldy. Split out the
display related debugfs code to a file of its own under display/,
initialized with a separate call. No functional changes.

v2:
- Also moved i915_frontbuffer_tracking, i915_gem_framebuffer,
i915_power_domain_info, i915_dmc_info, i915_ipc_status (Ville)

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200211161451.6867-2-jani.nikula@intel.com