Re: [PATCH 08/14] drm/i915: Complete crtc hw/uapi split, v3.

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Thu, Oct 24, 2019 at 02:47:59PM +0200, Maarten Lankhorst wrote:
> Now that we separated everything into uapi and hw, it's
> time to make the split definitive. Remove the union and
> make a copy of the hw state on modeset and fastset.
> 
> Color blobs are copied in crtc atomic_check(), right
> before color management is checked.
> 
> Changes since v1:
> - Copy all blobs immediately after drm_atomic_helper_check_modeset().
> - Clear crtc_state->hw on disable, instead of using clear_intel_crtc_state().
> Changes since v2:
> - Use intel_crtc_free_hw_state + clear in intel_crtc_disable_noatomic().
> - Make a intel_crtc_prepare_state() function that clears the crtc_state
>   and copies hw members.
> - Remove setting uapi.adjusted_mode, we now have a direct call to
>   drm_calc_timestamping_constants().
> 
> Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_atomic.c   | 44 +++++++++++++++
>  drivers/gpu/drm/i915/display/intel_atomic.h   |  2 +
>  drivers/gpu/drm/i915/display/intel_display.c  | 56 +++++++++++++++----
>  .../drm/i915/display/intel_display_types.h    |  9 +--
>  4 files changed, 95 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_atomic.c b/drivers/gpu/drm/i915/display/intel_atomic.c
> index 7cf13b9c7d38..266d0ce9d03d 100644
> --- a/drivers/gpu/drm/i915/display/intel_atomic.c
> +++ b/drivers/gpu/drm/i915/display/intel_atomic.c
> @@ -195,6 +195,14 @@ intel_crtc_duplicate_state(struct drm_crtc *crtc)
>  
>  	__drm_atomic_helper_crtc_duplicate_state(crtc, &crtc_state->uapi);
>  
> +	/* copy color blobs */
> +	if (crtc_state->hw.degamma_lut)
> +		drm_property_blob_get(crtc_state->hw.degamma_lut);
> +	if (crtc_state->hw.ctm)
> +		drm_property_blob_get(crtc_state->hw.ctm);
> +	if (crtc_state->hw.gamma_lut)
> +		drm_property_blob_get(crtc_state->hw.gamma_lut);
> +
>  	crtc_state->update_pipe = false;
>  	crtc_state->disable_lp_wm = false;
>  	crtc_state->disable_cxsr = false;
> @@ -208,6 +216,41 @@ intel_crtc_duplicate_state(struct drm_crtc *crtc)
>  	return &crtc_state->uapi;
>  }
>  
> +static void intel_crtc_put_color_blobs(struct intel_crtc_state *crtc_state)
> +{
> +	drm_property_blob_put(crtc_state->hw.degamma_lut);
> +	drm_property_blob_put(crtc_state->hw.gamma_lut);
> +	drm_property_blob_put(crtc_state->hw.ctm);
> +}
> +
> +void intel_crtc_free_hw_state(struct intel_crtc_state *crtc_state)
> +{
> +	intel_crtc_put_color_blobs(crtc_state);
> +}
> +
> +void intel_crtc_copy_color_blobs(struct intel_crtc_state *crtc_state)

This is only used in intel_display.c so should perhaps live there?

> +{
> +	intel_crtc_put_color_blobs(crtc_state);
> +
> +	if (crtc_state->uapi.degamma_lut)
> +		crtc_state->hw.degamma_lut =
> +			drm_property_blob_get(crtc_state->uapi.degamma_lut);
> +	else
> +		crtc_state->hw.degamma_lut = NULL;
> +
> +	if (crtc_state->uapi.gamma_lut)
> +		crtc_state->hw.gamma_lut =
> +			drm_property_blob_get(crtc_state->uapi.gamma_lut);
> +	else
> +		crtc_state->hw.gamma_lut = NULL;
> +
> +	if (crtc_state->uapi.ctm)
> +		crtc_state->hw.ctm =
> +			drm_property_blob_get(crtc_state->uapi.ctm);
> +	else
> +		crtc_state->hw.ctm = NULL;
> +}
> +
>  /**
>   * intel_crtc_destroy_state - destroy crtc state
>   * @crtc: drm crtc
> @@ -223,6 +266,7 @@ intel_crtc_destroy_state(struct drm_crtc *crtc,
>  	struct intel_crtc_state *crtc_state = to_intel_crtc_state(state);
>  
>  	__drm_atomic_helper_crtc_destroy_state(&crtc_state->uapi);
> +	intel_crtc_free_hw_state(crtc_state);
>  	kfree(crtc_state);
>  }
>  
> diff --git a/drivers/gpu/drm/i915/display/intel_atomic.h b/drivers/gpu/drm/i915/display/intel_atomic.h
> index 58065d3161a3..42be91e0772a 100644
> --- a/drivers/gpu/drm/i915/display/intel_atomic.h
> +++ b/drivers/gpu/drm/i915/display/intel_atomic.h
> @@ -35,6 +35,8 @@ intel_digital_connector_duplicate_state(struct drm_connector *connector);
>  struct drm_crtc_state *intel_crtc_duplicate_state(struct drm_crtc *crtc);
>  void intel_crtc_destroy_state(struct drm_crtc *crtc,
>  			       struct drm_crtc_state *state);
> +void intel_crtc_free_hw_state(struct intel_crtc_state *crtc_state);
> +void intel_crtc_copy_color_blobs(struct intel_crtc_state *crtc_state);
>  struct drm_atomic_state *intel_atomic_state_alloc(struct drm_device *dev);
>  void intel_atomic_state_clear(struct drm_atomic_state *state);
>  
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index 11dd7a182543..2dbc1df9505a 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -7110,6 +7110,8 @@ static void intel_crtc_disable_noatomic(struct drm_crtc *crtc,
>  	crtc->enabled = false;
>  	crtc->state->connector_mask = 0;
>  	crtc->state->encoder_mask = 0;
> +	intel_crtc_free_hw_state(crtc_state);
> +	memset(&crtc_state->hw, 0, sizeof(crtc_state->hw));
>  
>  	for_each_encoder_on_crtc(crtc->dev, crtc, encoder)
>  		encoder->base.crtc = NULL;
> @@ -12482,22 +12484,50 @@ static bool check_digital_port_conflicts(struct intel_atomic_state *state)
>  	return ret;
>  }
>  
> +static void
> +intel_crtc_copy_uapi_to_hw_state(struct intel_crtc_state *crtc_state)
> +{
> +	crtc_state->hw.enable = crtc_state->uapi.enable;
> +	crtc_state->hw.active = crtc_state->uapi.active;
> +	crtc_state->hw.mode = crtc_state->uapi.mode;
> +	crtc_state->hw.adjusted_mode = crtc_state->uapi.adjusted_mode;
> +	intel_crtc_copy_color_blobs(crtc_state);
> +}
> +
> +static void copy_hw_to_uapi_state(struct intel_crtc_state *crtc_state)
> +{
> +	crtc_state->uapi.enable = crtc_state->hw.enable;
> +	crtc_state->uapi.active = crtc_state->hw.active;
> +	crtc_state->uapi.mode = crtc_state->hw.mode;
> +	crtc_state->uapi.adjusted_mode = crtc_state->hw.adjusted_mode;

Why are we not copying the color blobs?

> +}
> +
>  static int
> -clear_intel_crtc_state(struct intel_crtc_state *crtc_state)
> +intel_crtc_prepare_state(struct intel_crtc_state *crtc_state)

Hmm. I was hoping we could make this even simpler, but maybe I'm a bit
naive. I guess we really do need to consider needs_modeset() so as to
not clobber the already computed hw state when we're not going to take
the full .compute_config() path.

>  {
>  	struct drm_i915_private *dev_priv =
>  		to_i915(crtc_state->uapi.crtc->dev);
>  	struct intel_crtc_state *saved_state;
>  
> +	if (!needs_modeset(crtc_state)) {
> +		/* Only need to update crtc_state->hw color blobs */

That comment is likely to get out of date. Not sure how to word it in a
nice way though. Essentially we just want to copy the part of the state
that doesn't clobber anything set up by .compute_config() & co.

It would be nice if we had the same level of abstraction for this case
as for the full modeset case. Eg. intel_crtc_copy_hw_state_non_modeset()
or something. A bit ugly that name though. Might have think of something
better.

Another thing that's a bit confusing is that we need to do the
intel_crtc_free_hw_state() for the full modeset path, but we don't
need it for the non-modeset path. Would be nice it the two paths
behaved more uniformly.

> +		intel_crtc_copy_color_blobs(crtc_state);
> +		return 0;
> +	}
> +
>  	saved_state = kzalloc(sizeof(*saved_state), GFP_KERNEL);
>  	if (!saved_state)
>  		return -ENOMEM;
>  
> +	/* free the old crtc_state->hw members */
> +	intel_crtc_free_hw_state(crtc_state);
> +
>  	/* FIXME: before the switch to atomic started, a new pipe_config was
>  	 * kzalloc'd. Code that depends on any field being zero should be
>  	 * fixed, so that the crtc_state can be safely duplicated. For now,
>  	 * only fields that are know to not cause problems are preserved. */
>  
> +	saved_state->uapi = crtc_state->uapi;
>  	saved_state->scaler_state = crtc_state->scaler_state;
>  	saved_state->shared_dpll = crtc_state->shared_dpll;
>  	saved_state->dpll_hw_state = crtc_state->dpll_hw_state;
> @@ -12515,14 +12545,11 @@ clear_intel_crtc_state(struct intel_crtc_state *crtc_state)
>  		saved_state->sync_mode_slaves_mask =
>  			crtc_state->sync_mode_slaves_mask;
>  
> -	/* Keep base drm_crtc_state intact, only clear our extended struct */
> -	BUILD_BUG_ON(offsetof(struct intel_crtc_state, base));
> -	BUILD_BUG_ON(offsetof(struct intel_crtc_state, uapi));
> -	BUILD_BUG_ON(offsetof(struct intel_crtc_state, hw));
> -	memcpy(&crtc_state->uapi + 1, &saved_state->uapi + 1,
> -	       sizeof(*crtc_state) - sizeof(crtc_state->uapi));
> -
> +	memcpy(crtc_state, saved_state, sizeof(*crtc_state));
>  	kfree(saved_state);
> +
> +	intel_crtc_copy_uapi_to_hw_state(crtc_state);
> +
>  	return 0;
>  }
>  
> @@ -12538,10 +12565,6 @@ intel_modeset_pipe_config(struct intel_crtc_state *pipe_config)
>  	int i;
>  	bool retry = true;
>  
> -	ret = clear_intel_crtc_state(pipe_config);
> -	if (ret)
> -		return ret;
> -
>  	pipe_config->cpu_transcoder =
>  		(enum transcoder) to_intel_crtc(crtc)->pipe;
>  
> @@ -13361,6 +13384,8 @@ verify_crtc_state(struct intel_crtc *crtc,
>  
>  	state = old_crtc_state->uapi.state;
>  	__drm_atomic_helper_crtc_destroy_state(&old_crtc_state->uapi);
> +	intel_crtc_free_hw_state(old_crtc_state);
> +
>  	pipe_config = old_crtc_state;
>  	memset(pipe_config, 0, sizeof(*pipe_config));
>  	pipe_config->uapi.crtc = &crtc->base;
> @@ -13823,6 +13848,10 @@ static int intel_atomic_check(struct drm_device *dev,
>  
>  	for_each_oldnew_intel_crtc_in_state(state, crtc, old_crtc_state,
>  					    new_crtc_state, i) {
> +		ret = intel_crtc_prepare_state(new_crtc_state);
> +		if (ret)
> +			return ret;

I have a feeling this should be its own loop in case we need
to insert global stuff after this.

For example, I think the port sync stuff should be there but
I can't see it now. Ah, for some reason it's buried deep inside
intel_modeset_pipe_config() which seems wrong. If any (or at
least the master) of the genlocked pipes does a full modeset
we need to do a full modeset on all of them, which should also
mean a full .compute_config() on everything.

Hmm. And if we do that then combining the uapi->hw copy and
clear_intel_crtc_state() like this is not going to work.

> +
>  		if (!needs_modeset(new_crtc_state))
>  			continue;
>  
> @@ -17099,6 +17128,7 @@ static void intel_modeset_readout_hw_state(struct drm_device *dev)
>  			to_intel_crtc_state(crtc->base.state);
>  
>  		__drm_atomic_helper_crtc_destroy_state(&crtc_state->uapi);
> +		intel_crtc_free_hw_state(crtc_state);
>  		memset(crtc_state, 0, sizeof(*crtc_state));
>  		__drm_atomic_helper_crtc_reset(&crtc->base, &crtc_state->uapi);
>  
> @@ -17227,6 +17257,7 @@ static void intel_modeset_readout_hw_state(struct drm_device *dev)
>  			 * set a flag to indicate that a full recalculation is
>  			 * needed on the next commit.
>  			 */
> +			crtc_state->hw.mode = crtc->base.mode;
>  			crtc_state->hw.mode.private_flags = I915_MODE_FLAG_INHERITED;
>  
>  			intel_crtc_compute_pixel_rate(crtc_state);
> @@ -17257,6 +17288,7 @@ static void intel_modeset_readout_hw_state(struct drm_device *dev)
>  
>  		intel_bw_crtc_update(bw_state, crtc_state);
>  
> +		copy_hw_to_uapi_state(crtc_state);
>  		intel_pipe_config_sanity_check(dev_priv, crtc_state);
>  	}
>  }
> diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
> index 4697f719b3a8..17c9ec300f18 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> @@ -749,8 +749,6 @@ enum intel_output_format {
>  };
>  
>  struct intel_crtc_state {
> -	union {
> -	struct drm_crtc_state base;
>  	/*
>  	 * uapi (drm) state. This is the software state shown to userspace.
>  	 * In particular, the following members are used for bookkeeping:
> @@ -773,8 +771,11 @@ struct intel_crtc_state {
>  	 *
>  	 * During initial hw readout, they need to be copied to uapi.
>  	 */
> -	struct drm_crtc_state hw;
> -	};
> +	struct {
> +		bool active, enable;
> +		struct drm_property_blob *degamma_lut, *gamma_lut, *ctm;
> +		struct drm_display_mode mode, adjusted_mode;
> +	} hw;
>  
>  	/**
>  	 * quirks - bitfield with hw state readout quirks
> -- 
> 2.23.0
> 
> _______________________________________________
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> Intel-gfx@lists.freedesktop.org
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-- 
Ville Syrjälä
Intel
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