[Intel-gfx] [PATCH 3/4] drm/i915/dp: Fix MST disable sequences

Ville Syrjälä ville.syrjala at linux.intel.com
Tue Dec 10 21:38:50 UTC 2019


On Fri, Dec 06, 2019 at 05:18:31PM -0800, José Roberto de Souza wrote:
> The disable sequence after wait for transcoder off was not correctly
> implemented.
> The MST disable sequence is basically the same for HSW, SKL, ICL and
> TGL, with just minor changes for TGL.
> 
> So here calling a new MST function to do the MST sequences, most of
> the steps just moved from the post disable hook.
> 
> With this last patch we finally fixed the hotplugs triggered by MST
> sinks during the disable/enable sequence, those were causing source
> to try to do a link training while it was not ready causing CPU pipe
> FIFO underrrus on TGL.
> 
> BSpec: 4231
> BSpec: 4163
> BSpec: 22243
> BSpec: 49190
> Cc: Lucas De Marchi <lucas.demarchi at intel.com>
> Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_ddi.c     | 17 +++--
>  drivers/gpu/drm/i915/display/intel_display.c |  2 +
>  drivers/gpu/drm/i915/display/intel_dp_mst.c  | 79 ++++++++++++++++----
>  drivers/gpu/drm/i915/display/intel_dp_mst.h  |  1 +
>  4 files changed, 79 insertions(+), 20 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
> index be5bc506d4d3..f06c6dfec888 100644
> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> @@ -34,6 +34,7 @@
>  #include "intel_ddi.h"
>  #include "intel_display_types.h"
>  #include "intel_dp.h"
> +#include "intel_dp_mst.h"
>  #include "intel_dp_link_training.h"
>  #include "intel_dpio_phy.h"
>  #include "intel_dsi.h"
> @@ -1953,17 +1954,19 @@ void intel_ddi_disable_transcoder_func(const struct intel_crtc_state *crtc_state
>  	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
>  	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
>  	enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
> -	i915_reg_t reg = TRANS_DDI_FUNC_CTL(cpu_transcoder);
> -	u32 val = I915_READ(reg);
> +	u32 val;
> +
> +	val = I915_READ(TRANS_DDI_FUNC_CTL(cpu_transcoder));
> +	val &= ~TRANS_DDI_FUNC_ENABLE;
>  
>  	if (INTEL_GEN(dev_priv) >= 12) {
> -		val &= ~(TRANS_DDI_FUNC_ENABLE | TGL_TRANS_DDI_PORT_MASK |
> -			 TRANS_DDI_DP_VC_PAYLOAD_ALLOC);
> +		if (!intel_crtc_has_type(crtc_state, INTEL_OUTPUT_DP_MST) ||
> +		    intel_dp_mst_is_slave_trans(crtc_state))
> +			val &= ~TGL_TRANS_DDI_PORT_MASK;
>  	} else {
> -		val &= ~(TRANS_DDI_FUNC_ENABLE | TRANS_DDI_PORT_MASK |
> -			 TRANS_DDI_DP_VC_PAYLOAD_ALLOC);
> +		val &= ~TRANS_DDI_PORT_MASK;
>  	}
> -	I915_WRITE(reg, val);
> +	I915_WRITE(TRANS_DDI_FUNC_CTL(cpu_transcoder), val);
>  
>  	if (dev_priv->quirks & QUIRK_INCREASE_DDI_DISABLED_TIME &&
>  	    intel_crtc_has_type(crtc_state, INTEL_OUTPUT_HDMI)) {
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index 2f74c0bfb2a8..d3eefb271fa4 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -6776,6 +6776,8 @@ static void haswell_crtc_disable(struct intel_atomic_state *state,
>  	if (!transcoder_is_dsi(cpu_transcoder))
>  		intel_disable_pipe(old_crtc_state);
>  
> +	intel_dp_mst_post_trans_disabled(old_crtc_state);
> +

Basically a new ad-hoc encoder hook :(

I think we either want to suck in more crap from the crtc_enable/disable
into the encoder hooks, or we try to move everything from the current
.post_disable() into .post_pll_disable() and relocate .post_disabel()
to a better place in the sequence. Though the whole .post_pll_disable()
is a farily poor match for these platforms as there's nothing to do after
disabling the PLL. So from the hook naming POV I'd kinda want move things
the other way.

So I think moving more things into the encoder hooks sounds like a
better plan. Eg. in this case I think we could probably shovel everything
after intel_pipe_disable() into .post_disable(). Would also help us
eliminate some of those 'if !dsi' things.

I'm also thinking intel_disable_ddi_buf() should be split up and
just inlined into the proper place(s). Would help in making the sequence
more easily comparable with the spec.


>  	if (INTEL_GEN(dev_priv) >= 11)
>  		icl_disable_transcoder_port_sync(old_crtc_state);
>  
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> index 49f1518e3ab9..3c98a25e6308 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> @@ -365,6 +365,57 @@ static void intel_mst_disable_dp(struct intel_encoder *encoder,
>  					  old_crtc_state, old_conn_state);
>  }
>  
> +static void
> +dp_mst_post_trans_disabled(struct intel_encoder *encoder,
> +			   const struct intel_crtc_state *old_crtc_state,
> +			   const struct drm_connector_state *old_conn_state)
> +{
> +	struct intel_dp_mst_encoder *intel_mst = enc_to_mst(&encoder->base);
> +	struct intel_digital_port *intel_dig_port = intel_mst->primary;
> +	struct intel_dp *intel_dp = &intel_dig_port->dp;
> +	struct intel_connector *connector =
> +		to_intel_connector(old_conn_state->connector);
> +	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
> +	u32 val;
> +
> +	drm_dp_update_payload_part2(&intel_dp->mst_mgr);
> +
> +	val = I915_READ(TRANS_DDI_FUNC_CTL(old_crtc_state->cpu_transcoder));
> +	val &= ~TRANS_DDI_DP_VC_PAYLOAD_ALLOC;
> +	I915_WRITE(TRANS_DDI_FUNC_CTL(old_crtc_state->cpu_transcoder), val);
> +
> +	if (intel_de_wait_for_set(dev_priv, intel_dp->regs.dp_tp_status,
> +				  DP_TP_STATUS_ACT_SENT, 1))
> +		DRM_ERROR("Timed out waiting for ACT sent when disabling\n");
> +
> +	drm_dp_check_act_status(&intel_dp->mst_mgr);
> +
> +	drm_dp_mst_deallocate_vcpi(&intel_dp->mst_mgr, connector->port);
> +}
> +
> +void
> +intel_dp_mst_post_trans_disabled(const struct intel_crtc_state *old_crtc_state)
> +{
> +	struct drm_atomic_state *state = old_crtc_state->uapi.state;
> +	struct drm_connector_state *old_conn_state;
> +	struct drm_connector *conn;
> +	int i;
> +
> +	if (!intel_crtc_has_type(old_crtc_state, INTEL_OUTPUT_DP_MST))
> +		return;
> +
> +	for_each_old_connector_in_state(state, conn, old_conn_state, i) {
> +		struct intel_encoder *encoder;
> +
> +		if (old_conn_state->crtc != old_crtc_state->uapi.crtc)
> +			continue;
> +
> +		encoder = to_intel_encoder(old_conn_state->best_encoder);
> +		dp_mst_post_trans_disabled(encoder, old_crtc_state,
> +					   old_conn_state);
> +	}
> +}
> +
>  static void intel_mst_post_disable_dp(struct intel_encoder *encoder,
>  				      const struct intel_crtc_state *old_crtc_state,
>  				      const struct drm_connector_state *old_conn_state)
> @@ -383,6 +434,12 @@ static void intel_mst_post_disable_dp(struct intel_encoder *encoder,
>  	WARN_ON(INTEL_GEN(dev_priv) >= 12 && last_mst_stream &&
>  		!intel_dp_mst_is_master_trans(old_crtc_state));
>  
> +	/*
> +	 * Power down mst path before disabling the port, otherwise we end
> +	 * up getting interrupts from the sink upon detecting link loss.
> +	 */
> +	drm_dp_send_power_updown_phy(&intel_dp->mst_mgr, connector->port,
> +				     false);
>  	/*
>  	 * From TGL spec: "If multi-stream slave transcoder: Configure
>  	 * Transcoder Clock Select to direct no clock to the transcoder"
> @@ -393,24 +450,20 @@ static void intel_mst_post_disable_dp(struct intel_encoder *encoder,
>  	if (INTEL_GEN(dev_priv) < 12 || !last_mst_stream)
>  		intel_ddi_disable_pipe_clock(old_crtc_state);
>  
> -	/* this can fail */
> -	drm_dp_check_act_status(&intel_dp->mst_mgr);
> -	/* and this can also fail */
> -	drm_dp_update_payload_part2(&intel_dp->mst_mgr);
>  
> -	drm_dp_mst_deallocate_vcpi(&intel_dp->mst_mgr, connector->port);
> +	intel_mst->connector = NULL;
> +	if (last_mst_stream) {
> +		enum transcoder cpu_transcoder;
> +		u32 val;
>  
> -	/*
> -	 * Power down mst path before disabling the port, otherwise we end
> -	 * up getting interrupts from the sink upon detecting link loss.
> -	 */
> -	drm_dp_send_power_updown_phy(&intel_dp->mst_mgr, connector->port,
> -				     false);
> +		cpu_transcoder = old_crtc_state->cpu_transcoder;
> +		val = I915_READ(TRANS_DDI_FUNC_CTL(cpu_transcoder));
> +		val &= ~TGL_TRANS_DDI_PORT_MASK;

Unconditional TGL stuff?

> +		I915_WRITE(TRANS_DDI_FUNC_CTL(cpu_transcoder), val);
>  
> -	intel_mst->connector = NULL;
> -	if (last_mst_stream)
>  		intel_dig_port->base.post_disable(&intel_dig_port->base,
>  						  old_crtc_state, NULL);
> +	}
>  
>  	DRM_DEBUG_KMS("active links %d\n", intel_dp->active_mst_links);
>  }
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.h b/drivers/gpu/drm/i915/display/intel_dp_mst.h
> index e40767f78343..87f32fab90fc 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_mst.h
> +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.h
> @@ -16,5 +16,6 @@ void intel_dp_mst_encoder_cleanup(struct intel_digital_port *intel_dig_port);
>  int intel_dp_mst_encoder_active_links(struct intel_digital_port *intel_dig_port);
>  bool intel_dp_mst_is_master_trans(const struct intel_crtc_state *crtc_state);
>  bool intel_dp_mst_is_slave_trans(const struct intel_crtc_state *crtc_state);
> +void intel_dp_mst_post_trans_disabled(const struct intel_crtc_state *old_crtc_state);
>  
>  #endif /* __INTEL_DP_MST_H__ */
> -- 
> 2.24.0
> 
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-- 
Ville Syrjälä
Intel


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