Re: [Intel-gfx] [PATCH 05/11] drm/i915: Add support for disabling any CRTCs during HW readout/sanitization

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

On Wed, Apr 26, 2023 at 07:52:59PM +0300, Imre Deak wrote:
> During HW readout/sanitization CRTCs can be disabled only if they don't
> have an attached encoder (and so the encoder disable hooks don't need to
> be called). An upcoming patch will need to disable CRTCs also with an
> attached an encoder, so add support for this.
> 
> For bigjoiner configs the encoder disabling hooks require the slave CRTC
> states, so add these too to the atomic state. Since the connector atomic
> state is already up-to-date when the CRTC is disabled the connector
> state needs to be updated (reset) after the CRTC is disabled, make this
> so. Follow the proper order of disabling first all bigjoiner slaves,
> then any port synced CRTC slaves followed by the CRTC originally
> requested to be disabled.
> 
> Signed-off-by: Imre Deak <imre.deak@intel.com>
> ---
>  .../drm/i915/display/intel_modeset_setup.c    | 124 ++++++++++++++++--
>  1 file changed, 115 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_modeset_setup.c b/drivers/gpu/drm/i915/display/intel_modeset_setup.c
> index a66085cf82bab..f613c074187a2 100644
> --- a/drivers/gpu/drm/i915/display/intel_modeset_setup.c
> +++ b/drivers/gpu/drm/i915/display/intel_modeset_setup.c
> @@ -50,10 +50,39 @@ static void set_encoder_for_connector(struct intel_connector *connector,
>  	}
>  }
>  
> +static void reset_encoder_connector_state(struct intel_encoder *encoder)
> +{
> +	struct drm_i915_private *i915 = to_i915(encoder->base.dev);
> +	struct intel_connector *connector;
> +	struct drm_connector_list_iter conn_iter;
> +
> +	drm_connector_list_iter_begin(&i915->drm, &conn_iter);
> +	for_each_intel_connector_iter(connector, &conn_iter) {
> +		if (connector->base.encoder != &encoder->base)
> +			continue;
> +
> +		set_encoder_for_connector(connector, NULL);
> +
> +		connector->base.dpms = DRM_MODE_DPMS_OFF;
> +		connector->base.encoder = NULL;
> +	}
> +	drm_connector_list_iter_end(&conn_iter);
> +}
> +
> +static void reset_crtc_encoder_state(struct intel_crtc *crtc)
> +{
> +	struct drm_i915_private *i915 = to_i915(crtc->base.dev);
> +	struct intel_encoder *encoder;
> +
> +	for_each_encoder_on_crtc(&i915->drm, &crtc->base, encoder) {
> +		reset_encoder_connector_state(encoder);
> +		encoder->base.crtc = NULL;
> +	}
> +}
> +
>  static void intel_crtc_disable_noatomic(struct intel_crtc *crtc,
>  					struct drm_modeset_acquire_ctx *ctx)
>  {
> -	struct intel_encoder *encoder;
>  	struct drm_i915_private *i915 = to_i915(crtc->base.dev);
>  	struct intel_bw_state *bw_state =
>  		to_intel_bw_state(i915->display.bw.obj.state);
> @@ -65,9 +94,8 @@ static void intel_crtc_disable_noatomic(struct intel_crtc *crtc,
>  		to_intel_crtc_state(crtc->base.state);
>  	struct intel_plane *plane;
>  	struct drm_atomic_state *state;
> -	struct intel_crtc_state *temp_crtc_state;
> +	struct intel_crtc *temp_crtc;
>  	enum pipe pipe = crtc->pipe;
> -	int ret;
>  
>  	if (!crtc_state->hw.active)
>  		return;
> @@ -92,10 +120,17 @@ static void intel_crtc_disable_noatomic(struct intel_crtc *crtc,
>  	to_intel_atomic_state(state)->internal = true;
>  
>  	/* Everything's already locked, -EDEADLK can't happen. */
> -	temp_crtc_state = intel_atomic_get_crtc_state(state, crtc);
> -	ret = drm_atomic_add_affected_connectors(state, &crtc->base);
> +	for_each_intel_crtc_in_pipe_mask(&i915->drm, temp_crtc,
> +					 BIT(pipe) |
> +					 intel_crtc_bigjoiner_slave_pipes(crtc_state)) {
> +		struct intel_crtc_state *temp_crtc_state =
> +			intel_atomic_get_crtc_state(state, temp_crtc);
> +		int ret;
>  
> -	drm_WARN_ON(&i915->drm, IS_ERR(temp_crtc_state) || ret);
> +		ret = drm_atomic_add_affected_connectors(state, &temp_crtc->base);
> +
> +		drm_WARN_ON(&i915->drm, IS_ERR(temp_crtc_state) || ret);
> +	}

It's a bit weird to have this loop inside the function that
otherwise seems to be called individually for each of the
joined pipes. Why do we need this?

>  
>  	i915->display.funcs.display->crtc_disable(to_intel_atomic_state(state), crtc);
>  
> @@ -120,8 +155,7 @@ static void intel_crtc_disable_noatomic(struct intel_crtc *crtc,
>  	drm_WARN_ON(&i915->drm,
>  		    drm_atomic_set_mode_for_crtc(&crtc_state->uapi, NULL) < 0);
>  
> -	for_each_encoder_on_crtc(&i915->drm, &crtc->base, encoder)
> -		encoder->base.crtc = NULL;
> +	reset_crtc_encoder_state(crtc);
>  
>  	intel_fbc_disable(crtc);
>  	intel_update_watermarks(i915);
> @@ -272,6 +306,77 @@ static void intel_sanitize_fifo_underrun_reporting(const struct intel_crtc_state
>  					   !HAS_GMCH(i915));
>  }
>  
> +static u32 get_transcoder_pipes(struct drm_i915_private *i915, u32 transcoder_mask)
> +{
> +	struct intel_crtc *slave_crtc;
> +	u32 pipes = 0;
> +
> +	for_each_intel_crtc(&i915->drm, slave_crtc) {
> +		struct intel_crtc_state *slave_crtc_state =
> +			to_intel_crtc_state(slave_crtc->base.state);
> +
> +		if (slave_crtc_state->cpu_transcoder == INVALID_TRANSCODER)
> +			continue;
> +
> +		if (transcoder_mask & BIT(slave_crtc_state->cpu_transcoder))
> +			pipes |= BIT(slave_crtc->pipe);
> +	}
> +
> +	return pipes;
> +}
> +
> +static u32 get_bigjoiner_slave_pipes(struct drm_i915_private *i915, u32 master_pipes)
> +{
> +	struct intel_crtc *master_crtc;
> +	u32 pipes = 0;
> +
> +	for_each_intel_crtc_in_pipe_mask(&i915->drm, master_crtc, master_pipes) {
> +		struct intel_crtc_state *master_crtc_state =
> +			to_intel_crtc_state(master_crtc->base.state);
> +
> +		pipes |= intel_crtc_bigjoiner_slave_pipes(master_crtc_state);
> +	}
> +
> +	return pipes;
> +}
> +
> +static void kill_bigjoiner_slave_noatomic(struct intel_crtc *master_crtc)
> +{
> +	struct drm_i915_private *i915 = to_i915(master_crtc->base.dev);
> +	struct intel_crtc_state *master_crtc_state =
> +		to_intel_crtc_state(master_crtc->base.state);
> +	struct intel_crtc *slave_crtc;
> +
> +	for_each_intel_crtc_in_pipe_mask(&i915->drm, slave_crtc,
> +					 intel_crtc_bigjoiner_slave_pipes(master_crtc_state)) {
> +		struct intel_crtc_state *slave_crtc_state =
> +			to_intel_crtc_state(slave_crtc->base.state);
> +
> +		slave_crtc_state->bigjoiner_pipes = 0;
> +	}
> +
> +	master_crtc_state->bigjoiner_pipes = 0;
> +}
> +
> +static void disable_crtc_with_slaves(struct intel_crtc *crtc,
> +				     struct drm_modeset_acquire_ctx *ctx)
> +{
> +	struct drm_i915_private *i915 = to_i915(crtc->base.dev);
> +	struct intel_crtc_state *crtc_state = to_intel_crtc_state(crtc->base.state);
> +	u32 bigjoiner_masters = BIT(crtc->pipe) |
> +				get_transcoder_pipes(i915, crtc_state->sync_mode_slaves_mask);

The resulting bitmask would seem to also include the bigjoiner slaves.

> +	u32 bigjoiner_slaves = get_bigjoiner_slave_pipes(i915, bigjoiner_masters);
> +	struct intel_crtc *temp_crtc;
> +
> +	for_each_intel_crtc_in_pipe_mask(&i915->drm, temp_crtc, bigjoiner_slaves)
> +		intel_crtc_disable_noatomic(temp_crtc, ctx);
> +
> +	for_each_intel_crtc_in_pipe_mask(&i915->drm, temp_crtc, bigjoiner_masters) {
> +		intel_crtc_disable_noatomic(temp_crtc, ctx);
> +		kill_bigjoiner_slave_noatomic(temp_crtc);
> +	}
> +}
> +
>  static void intel_sanitize_crtc(struct intel_crtc *crtc,
>  				struct drm_modeset_acquire_ctx *ctx)
>  {
> @@ -299,10 +404,11 @@ static void intel_sanitize_crtc(struct intel_crtc *crtc,
>  	/*
>  	 * Adjust the state of the output pipe according to whether we have
>  	 * active connectors/encoders.
> +	 * TODO: Add support for MST
>  	 */
>  	if (crtc_state->hw.active && !intel_crtc_has_encoders(crtc) &&
>  	    !intel_crtc_is_bigjoiner_slave(crtc_state))
> -		intel_crtc_disable_noatomic(crtc, ctx);
> +		disable_crtc_with_slaves(crtc, ctx);

I'd like to keep the _noatomic() in the name.

>  }
>  
>  static bool has_bogus_dpll_config(const struct intel_crtc_state *crtc_state)
> -- 
> 2.37.2

-- 
Ville Syrjälä
Intel