[PATCH 00/31] Reconcile i915's and xe's display power mgt sequences

Tue Oct 8 15:24:42 UTC 2024

-----Original Message-----
From: Intel-gfx <intel-gfx-bounces at lists.freedesktop.org> On Behalf Of Rodrigo Vivi
Sent: Tuesday, September 24, 2024 1:35 PM
To: intel-gfx at lists.freedesktop.org; intel-xe at lists.freedesktop.org
Cc: Deak, Imre <imre.deak at intel.com>; Vivi, Rodrigo <rodrigo.vivi at intel.com>
Subject: [PATCH 00/31] Reconcile i915's and xe's display power mgt sequences
> 
> Reconcile i915's and xe's display power management sequences.
> 
> The main goal of this series is to ensure that the display
> power management sequences from both drivers are fully aligned.
> So, it needs to live under i915/display/ and xe_display_pm
> can only be a wrapper to check for the xe's module
> parameter before jumping in the i915/display functions.
> 
> During this process, it was clear that the Xe's runtime pm
> sequences for integrated gfx (non d3cold capable) was totally
> misaligned with i915 and prune to more bugs. So, this series ends
> up fixing this and bringing a full alignment there as well.
> 
> The one new thing under i915 is the d3cold sequences. Apparently
> that can be reduced, but for now this is what is validated and
> stable on both DG2 and BMG. So, let's move that to the
> i915/display side as well and continue on the improvements with
> the code in the right place.
> 
> When I started this work I was hoping that I could run more
> conversions to intel_display struct before moving things from
> i915_driver.c to intel_display_driver, however that was a deeper
> task and this series is already deep enough.
> 
> Cc: Imre Deak <imre.deak at intel.com>
> Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>

I did individual reviews of all 31 patches in the series, and I gave my
RB to all of them with some notes.  However, there were just a few
things that I felt I needed to say before we called this series closed.

Don't worry: none of this is blocking.

1. Are we sure that aligning i915 and Xe like this is the correct
course of action?  I've been reprimanded in the past for creating
patches whose overall conceit is "we do 'X' thing in 'Y' way on
i915, so we should also be doing 'X' thing in 'Y' way on Xe".  So, I
figured I should at least point this out.

2. Several patches in the series operate on both i915 and Xe at the
same time.  I don't think there's any strict rule stating that we can't
do something like that, but IMO we should consider splitting those
patches into i915 and Xe components where possible/logical.

3. When all is said and done, this series eventually puts all of the
driver management code into intel_display_driver.c.  So any
changes made to xe_display.c, for example, seem superfluous
given we're intending on centralizing the display code outside of
xe_display.c in the end.  It'd be a lot of work to reorder the patch
series, especially at this point, but if we needed to start again from
scratch for any reason, it might be worth ordering the changes as such:

	- Create all necessary helper functions in intel_display_driver
	   for i915 and Xe, using them in the i915 execution path.

	- Use the new helper functions in the xe execution path.

	- Create and use all necessary helper functions for the xe
	   execution path.

Again, none of this is blocking, so there's no need to upend everything
and start over.  I just felt I needed to state some of these things as a
part of due diligence.

Reviewed-by: Jonathan Cavitt <jonathan.cavitt at intel.com>
-Jonathan Cavitt

> 
> 
> Rodrigo Vivi (31):
>   drm/i915: Remove vga and gmbus seq out of i915_restore_display
>   drm/i915/display: Convert i915_suspend into i9xx_display_sr
>   drm/i915/display: Move regfile registers intel_display.restore
>   drm/i915/display: Move shutdown sequences under display driver
>   drm/xe: At shutdown disable commit helpers instead of flushing
>   drm/xe: Use i915-display shutdown sequence directly
>   drm/{i915,xe}/display: Move DP MST calls to display_driver
>   drm/i915/display: Move suspend sequences to intel_display_driver
>   drm/xe/display: Delay hpd_init resume
>   drm/xe/display: Spin-off xe_display runtime/d3cold sequences
>   drm/{i915,xe}: Consolidate display resume functions
>   drm/i915: Remove lingering pci_save_state
>   drm/{i915,xe}: Consolidate display suspend functions
>   drm/i915/display: Move resume sequences to intel_display_driver
>   drm/xe/display: Delay dsm handler registration
>   drm/{i915,xe}: Move power_domains suspend/resume to display_power
>   drm/{i915,xe}: Move remaining intel_power_domains to intel_display
>   drm/i915/display: Split resume_noirq calls for now
>   drm/xe/display: Align display resume sequence with i915
>   drm/xe/display: Align suspend sequence with i915
>   drm/{i915,xe}/display: Move dsm registration under intel_driver
>   drm/i915/display: Move runtime pm related calls under
>     intel_display_driver
>   drm/xe/display: Prepare runtime pm functions
>   drm/xe/display: Call intel_hpd_init on every runtime resume
>   drm/xe/display: Move hpd_poll calls to later runtime stages
>   drm/xe/display: Add missing watermark ipc update at runtime resume
>   drm/xe/display: Notify opregion upon runtime suspend/resume non-d3cold
>   drm/xe/display: Move display runtime suspend to a later point
>   drm/xe/display: Kill crtc commit flush
>   drm/xe/display: Add missing power display handling on non-d3cold rpm
>   drm/{i915,xe}/display: Consolidade entire runtime pm sequence
> 
>  drivers/gpu/drm/i915/Makefile                 |   2 +-
>  .../gpu/drm/i915/display/i9xx_display_sr.c    |  99 +++++++
>  .../gpu/drm/i915/display/i9xx_display_sr.h    |  14 +
>  .../gpu/drm/i915/display/intel_display_core.h |   5 +
>  .../drm/i915/display/intel_display_driver.c   | 247 ++++++++++++++++++
>  .../drm/i915/display/intel_display_driver.h   |  18 ++
>  .../drm/i915/display/intel_display_power.c    |   6 +-
>  .../drm/i915/display/intel_display_power.h    |   2 +-
>  drivers/gpu/drm/i915/i915_driver.c            | 161 ++----------
>  drivers/gpu/drm/i915/i915_drv.h               |   9 -
>  drivers/gpu/drm/i915/i915_suspend.c           | 141 ----------
>  drivers/gpu/drm/i915/i915_suspend.h           |  14 -
>  drivers/gpu/drm/xe/display/xe_display.c       | 185 ++++---------
>  drivers/gpu/drm/xe/display/xe_display.h       |  11 +-
>  drivers/gpu/drm/xe/display/xe_fb_pin.c        |   8 +
>  drivers/gpu/drm/xe/xe_device.c                |   4 +-
>  drivers/gpu/drm/xe/xe_pm.c                    |  16 +-
>  17 files changed, 498 insertions(+), 444 deletions(-)
>  create mode 100644 drivers/gpu/drm/i915/display/i9xx_display_sr.c
>  create mode 100644 drivers/gpu/drm/i915/display/i9xx_display_sr.h
>  delete mode 100644 drivers/gpu/drm/i915/i915_suspend.c
>  delete mode 100644 drivers/gpu/drm/i915/i915_suspend.h
> 
> -- 
> 2.46.0
> 
> 