[Intel-gfx] [PATCH v13 13/14] drm/i915/dp: Enable Upfront link training for typeC DP support on HSW/BDW/SKL/BXT (DDI platforms)

Manasi Navare manasi.d.navare at intel.com
Thu Sep 8 15:06:56 UTC 2016


On Thu, Sep 08, 2016 at 03:10:43PM +0300, Mika Kahola wrote:
> On Wed, 2016-09-07 at 11:28 -0700, Manasi Navare wrote:
> > From: Durgadoss R <durgadoss.r at intel.com>
> > 
> > To support USB type C alternate DP mode, the display driver needs to
> > know the number of lanes required by the DP panel as well as number
> > of lanes that can be supported by the type-C cable. Sometimes, the
> > type-C cable may limit the bandwidth even if Panel can support
> > more lanes. To address these scenarios, the display driver will
> > start link training with max lanes, and if that fails, the driver
> > falls back to x2 lanes; and repeats this procedure for all
> > bandwidth/lane configurations.
> > 
> > * Since link training is done before modeset only the port
> >   (and not pipe/planes) and its associated PLLs are enabled.
> > * On DP hotplug: Directly start link training on the DP encoder.
> > * On Connected boot scenarios: When booted with an LFP and a DP,
> >   sometimes BIOS brings up DP. In these cases, we disable the
> >   crtc and then do upfront link training; and bring it back up.
> > * All local changes made for upfront link training are reset
> >   to their previous values once it is done; so that the
> >   subsequent modeset is not aware of these changes.
> > 
> > Changes since v12:
> > * Fix Rebase issues (Mika Kahola)
> > Changes since v11:
> > * Change the fallback link rate logic (Manasi)
> > Changes since v10:
> > * Use the ddi link train function that loops through all the link
> > rates
> > and lane counts starting from the highest supported (Manasi)
> > * For upfront link training, set the upfront flag so that the link
> > can
> > be disabled after caching upfront values (Manasi)
> > Changes since v9:
> > * Change the macros to use dev_priv in place of dev (David Weinehall)
> > Changes since v8:
> > * Reset upfront lane count and link rate values on HPD
> > for DP connector physical disconnect (Manasi)
> > Changes since v7:
> > * Move the upfront link training to intel_dp_mode_valid()
> >   to avoid a race condition with DP MST sideband comms. (Ville)
> > Changes since v6:
> > * Fix some initialization bugs on link_rate (Jim Bride)
> > * Use link_rate (and not link_bw) for upfront (Ville)
> > * Make intel_dp_upfront*() as a vfunc (Ander)
> > * The train_set_valid variable in intel_dp was removed due to
> >   issues in fast link training. So, to indicate the link train
> >   status, move the channel_eq inside intel_dp.
> > Changes since v5:
> > * Moved retry logic in upfront to intel_dp.c so that it
> >   can be used for all platforms.
> > Changes since v4:
> > * Removed usage of crtc_state in upfront link training;
> >   Hence no need to find free crtc to do upfront now.
> > * Re-enable crtc if it was disabled for upfront.
> > * Use separate variables to track max lane count
> >   and link rate found by upfront, without modifying
> >   the original DPCD read from panel.
> > Changes since v3:
> > * Fixed a return value on BXT check
> > * Reworked on top of bxt_ddi_pll_select split from Ander
> > * Renamed from ddi_upfront to bxt_upfront since the
> >   upfront logic includes BXT specific functions for now.
> > Changes since v2:
> > * Rebased on top of latest dpll_mgr.c code and
> >   latest HPD related clean ups.
> > * Corrected return values from upfront (Ander)
> > * Corrected atomic locking for upfront in intel_dp.c (Ville)
> > Changes since v1:
> > *  all pll related functions inside ddi.c
> > 
> > Signed-off-by: Durgadoss R <durgadoss.r at intel.com>
> > Signed-off-by: Jim Bride <jim.bride at linux.intel.com>
> > Signed-off-by: Manasi Navare <manasi.d.navare at intel.com>
> > ---
> >  drivers/gpu/drm/i915/intel_ddi.c              |  21 +-
> >  drivers/gpu/drm/i915/intel_dp.c               | 376
> > +++++++++++++++++++-------
> >  drivers/gpu/drm/i915/intel_dp_link_training.c |   1 -
> >  drivers/gpu/drm/i915/intel_drv.h              |  14 +-
> >  4 files changed, 310 insertions(+), 102 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_ddi.c
> > b/drivers/gpu/drm/i915/intel_ddi.c
> > index da2b804..b32f7ba 100644
> > --- a/drivers/gpu/drm/i915/intel_ddi.c
> > +++ b/drivers/gpu/drm/i915/intel_ddi.c
> > @@ -1673,7 +1673,8 @@ static void intel_ddi_pre_enable_dp(struct
> > intel_encoder *encoder,
> >  	pll->config.crtc_mask = 0;
> >  
> >  	/* If Link Training fails, send a uevent to generate a
> > hotplug */
> > -	if (!(intel_ddi_link_train(intel_dp, link_rate, lane_count,
> > link_mst)))
> > +	if (!(intel_ddi_link_train(intel_dp, link_rate, lane_count,
> > link_mst,
> > +				   false)))
> >  		drm_kms_helper_hotplug_event(encoder->base.dev);
> >  	pll->config = tmp_pll_config;
> >  }
> > @@ -2460,7 +2461,7 @@ intel_ddi_get_link_dpll(struct intel_dp
> > *intel_dp, int clock)
> >  
> >  bool
> >  intel_ddi_link_train(struct intel_dp *intel_dp, int max_link_rate,
> > -		     uint8_t max_lane_count, bool link_mst)
> > +		     uint8_t max_lane_count, bool link_mst, bool
> > is_upfront)
> >  {
> >  	struct intel_connector *connector = intel_dp-
> > >attached_connector;
> >  	struct intel_encoder *encoder = connector->encoder;
> > @@ -2506,6 +2507,7 @@ intel_ddi_link_train(struct intel_dp *intel_dp,
> > int max_link_rate,
> >  			pll->funcs.disable(dev_priv, pll);
> >  			pll->config = tmp_pll_config;
> >  		}
> > +
> >  		if (ret) {
> >  			DRM_DEBUG_KMS("Link Training successful at
> > link rate: "
> >  				      "%d lane:%d\n", link_rate,
> > lane_count);
> > @@ -2514,6 +2516,21 @@ intel_ddi_link_train(struct intel_dp
> > *intel_dp, int max_link_rate,
> >  	}
> >  	intel_dp_stop_link_train(intel_dp);
> >  
> > +	if (is_upfront) {
> > +		DRM_DEBUG_KMS("Upfront link train %s: link_clock:%d
> > lanes:%d\n",
> > +			      ret ? "Passed" : "Failed",
> > +			      link_rate, lane_count);
> > +		/* Disable port followed by PLL for next retry/clean
> > up */
> > +		intel_ddi_post_disable(encoder, NULL, NULL);
> > +		pll->funcs.disable(dev_priv, pll);
> > +		pll->config = tmp_pll_config;
> > +		if (ret) {
> > +			/* Save the upfront values */
> > +			intel_dp->max_lanes_upfront = lane_count;
> > +			intel_dp->max_link_rate_upfront = link_rate;
> > +		}
> > +	}
> > +
> >  	if (!lane_count)
> >  		DRM_ERROR("Link Training Failed\n");
> >  
> > diff --git a/drivers/gpu/drm/i915/intel_dp.c
> > b/drivers/gpu/drm/i915/intel_dp.c
> > index 714fbe3..7794180 100644
> > --- a/drivers/gpu/drm/i915/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/intel_dp.c
> > @@ -153,12 +153,21 @@ intel_dp_max_link_bw(struct
> > intel_dp  *intel_dp)
> >  static u8 intel_dp_max_lane_count(struct intel_dp *intel_dp)
> >  {
> >  	struct intel_digital_port *intel_dig_port =
> > dp_to_dig_port(intel_dp);
> > -	u8 source_max, sink_max;
> > +	u8 temp, source_max, sink_max;
> >  
> >  	source_max = intel_dig_port->max_lanes;
> >  	sink_max = drm_dp_max_lane_count(intel_dp->dpcd);
> >  
> > -	return min(source_max, sink_max);
> > +	temp = min(source_max, sink_max);
> > +
> > +	/*
> > +	 * Limit max lanes w.r.t to the max value found
> > +	 * using Upfront link training also.
> > +	 */
> > +	if (intel_dp->max_lanes_upfront)
> > +		return min(temp, intel_dp->max_lanes_upfront);
> > +	else
> > +		return temp;
> >  }
> >  
> >  /*
> > @@ -190,6 +199,229 @@ intel_dp_max_data_rate(int max_link_clock, int
> > max_lanes)
> >  	return (max_link_clock * max_lanes * 8) / 10;
> >  }
> >  
> > +static int intel_dp_upfront_crtc_disable(struct intel_crtc *crtc,
> > +				struct drm_modeset_acquire_ctx *ctx,
> > +				bool enable)
> Indentation seems a bit off.
>

Yep, will fix that and resubmit.

 
> > +{
> > +	int ret;
> > +	struct drm_atomic_state *state;
> > +	struct intel_crtc_state *crtc_state;
> > +	struct drm_device *dev = crtc->base.dev;
> > +	enum pipe pipe = crtc->pipe;
> > +
> > +	state = drm_atomic_state_alloc(dev);
> > +	if (!state)
> > +		return -ENOMEM;
> > +
> > +	state->acquire_ctx = ctx;
> > +
> > +	crtc_state = intel_atomic_get_crtc_state(state, crtc);
> > +	if (IS_ERR(crtc_state)) {
> > +		ret = PTR_ERR(crtc_state);
> > +		drm_atomic_state_free(state);
> > +		return ret;
> > +	}
> > +
> > +	DRM_DEBUG_KMS("%sabling crtc %c %s upfront link train\n",
> > +			enable ? "En" : "Dis",
> > +			pipe_name(pipe),
> > +			enable ? "after" : "before");
> > +
> > +	crtc_state->base.active = enable;
> > +	ret = drm_atomic_commit(state);
> > +	if (ret)
> > +		drm_atomic_state_free(state);
> > +
> > +	return ret;
> > +}
> > +
> > +static int
> > +intel_dp_sink_rates(struct intel_dp *intel_dp, const int
> > **sink_rates)
> > +{
> > +	if (intel_dp->num_sink_rates) {
> > +		*sink_rates = intel_dp->sink_rates;
> > +		return intel_dp->num_sink_rates;
> > +	}
> > +
> > +	*sink_rates = default_rates;
> > +
> > +	return (intel_dp_max_link_bw(intel_dp) >> 3) + 1;
> > +}
> > +
> > +bool intel_dp_source_supports_hbr2(struct intel_dp *intel_dp)
> > +{
> > +	struct intel_digital_port *dig_port =
> > dp_to_dig_port(intel_dp);
> > +	struct drm_i915_private *dev_priv = to_i915(dig_port-
> > >base.base.dev);
> > +
> > +	/* WaDisableHBR2:skl */
> > +	if (IS_SKL_REVID(dev_priv, 0, SKL_REVID_B0))
> > +		return false;
> > +
> > +	if ((IS_HASWELL(dev_priv) && !IS_HSW_ULX(dev_priv)) ||
> > +	    IS_BROADWELL(dev_priv) || (INTEL_GEN(dev_priv) >= 9))
> > +		return true;
> > +	else
> > +		return false;
> > +}
> > +
> > +static int
> > +intel_dp_source_rates(struct intel_dp *intel_dp, const int
> > **source_rates)
> > +{
> > +	struct intel_digital_port *dig_port =
> > dp_to_dig_port(intel_dp);
> > +	struct drm_i915_private *dev_priv = to_i915(dig_port-
> > >base.base.dev);
> > +	int size;
> > +
> > +	if (IS_BROXTON(dev_priv)) {
> > +		*source_rates = bxt_rates;
> > +		size = ARRAY_SIZE(bxt_rates);
> > +	} else if (IS_SKYLAKE(dev_priv) || IS_KABYLAKE(dev_priv)) {
> > +		*source_rates = skl_rates;
> > +		size = ARRAY_SIZE(skl_rates);
> > +	} else {
> > +		*source_rates = default_rates;
> > +		size = ARRAY_SIZE(default_rates);
> > +	}
> > +
> > +	/* This depends on the fact that 5.4 is last value in the
> > array */
> > +	if (!intel_dp_source_supports_hbr2(intel_dp))
> > +		size--;
> > +
> > +	return size;
> > +}
> > +
> > +static int intersect_rates(const int *source_rates, int source_len,
> > +			   const int *sink_rates, int sink_len,
> > +			   int *common_rates)
> > +{
> > +	int i = 0, j = 0, k = 0;
> > +
> > +	while (i < source_len && j < sink_len) {
> > +		if (source_rates[i] == sink_rates[j]) {
> > +			if (WARN_ON(k >= DP_MAX_SUPPORTED_RATES))
> > +				return k;
> > +			common_rates[k] = source_rates[i];
> > +			++k;
> > +			++i;
> > +			++j;
> > +		} else if (source_rates[i] < sink_rates[j]) {
> > +			++i;
> > +		} else {
> > +			++j;
> > +		}
> > +	}
> > +	return k;
> > +}
> > +
> > +static int intel_dp_common_rates(struct intel_dp *intel_dp,
> > +				 int *common_rates)
> > +{
> > +	const int *source_rates, *sink_rates;
> > +	int source_len, sink_len;
> > +
> > +	sink_len = intel_dp_sink_rates(intel_dp, &sink_rates);
> > +
> > +	/* Cap sink rates w.r.t upfront values */
> > +	if (intel_dp->max_link_rate_upfront) {
> > +		int len = sink_len - 1;
> > +		while (len > 0 && sink_rates[len] >
> > +		       intel_dp->max_link_rate_upfront)
> > +			len--;
> > +		sink_len = len + 1;
> > +	}
> > +
> > +	source_len = intel_dp_source_rates(intel_dp, &source_rates);
> > +
> > +	return intersect_rates(source_rates, source_len,
> > +			       sink_rates, sink_len,
> > +			       common_rates);
> > +}
> > +
> > +static bool intel_dp_upfront_link_train(struct intel_dp *intel_dp)
> > +{
> > +	struct intel_digital_port *intel_dig_port =
> > dp_to_dig_port(intel_dp);
> > +	struct intel_encoder *intel_encoder = &intel_dig_port->base;
> > +	struct drm_device *dev = intel_encoder->base.dev;
> > +	struct drm_i915_private *dev_priv = to_i915(dev);
> > +	struct drm_mode_config *config = &dev->mode_config;
> > +	struct drm_modeset_acquire_ctx ctx;
> > +	struct intel_crtc *intel_crtc;
> > +	struct drm_crtc *crtc = NULL;
> > +	struct intel_shared_dpll *pll;
> > +	struct intel_shared_dpll_config tmp_pll_config;
> > +	bool disable_dpll = false;
> > +	int ret;
> > +	bool done = false, has_mst = false;
> > +	uint8_t max_lanes;
> > +	int common_rates[DP_MAX_SUPPORTED_RATES] = {};
> > +	int common_len;
> > +	enum intel_display_power_domain power_domain;
> > +
> > +	power_domain =
> > intel_display_port_power_domain(intel_encoder);
> > +	intel_display_power_get(dev_priv, power_domain);
> > +
> > +	common_len = intel_dp_common_rates(intel_dp, common_rates);
> > +	max_lanes = intel_dp_max_lane_count(intel_dp);
> > +	if (WARN_ON(common_len <= 0))
> > +		return true;
> > +
> > +	drm_modeset_acquire_init(&ctx, 0);
> > +retry:
> > +	ret = drm_modeset_lock(&config->connection_mutex, &ctx);
> > +	if (ret)
> > +		goto exit_fail;
> > +
> > +	if (intel_encoder->base.crtc) {
> > +		crtc = intel_encoder->base.crtc;
> > +
> > +		ret = drm_modeset_lock(&crtc->mutex, &ctx);
> > +		if (ret)
> > +			goto exit_fail;
> > +
> > +		ret = drm_modeset_lock(&crtc->primary->mutex, &ctx);
> > +		if (ret)
> > +			goto exit_fail;
> > +
> > +		intel_crtc = to_intel_crtc(crtc);
> > +		pll = intel_crtc->config->shared_dpll;
> > +		disable_dpll = true;
> > +		has_mst = intel_crtc_has_type(intel_crtc->config,
> > +					      INTEL_OUTPUT_DP_MST);
> > +		ret = intel_dp_upfront_crtc_disable(intel_crtc,
> > &ctx, false);
> > +		if (ret)
> > +			goto exit_fail;
> > +	}
> > +
> > +	mutex_lock(&dev_priv->dpll_lock);
> > +	if (disable_dpll) {
> > +		/* Clear the PLL config state */
> > +		tmp_pll_config = pll->config;
> > +		pll->config.crtc_mask = 0;
> > +	}
> > +
> > +	done = intel_dp->upfront_link_train(intel_dp,
> > +					    common_rates[common_len-
> > 1],
> > +					    max_lanes,
> > +					    has_mst,
> > +					    true);
> > +	if (disable_dpll)
> > +		pll->config = tmp_pll_config;
> > +
> > +	mutex_unlock(&dev_priv->dpll_lock);
> > +
> > +	if (crtc)
> > +		ret = intel_dp_upfront_crtc_disable(intel_crtc,
> > &ctx, true);
> > +
> > +exit_fail:
> > +	if (ret == -EDEADLK) {
> > +		drm_modeset_backoff(&ctx);
> > +		goto retry;
> > +	}
> > +	drm_modeset_drop_locks(&ctx);
> > +	drm_modeset_acquire_fini(&ctx);
> > +	intel_display_power_put(dev_priv, power_domain);
> > +	return done;
> > +}
> > +
> >  static enum drm_mode_status
> >  intel_dp_mode_valid(struct drm_connector *connector,
> >  		    struct drm_display_mode *mode)
> > @@ -211,6 +443,19 @@ intel_dp_mode_valid(struct drm_connector
> > *connector,
> >  		target_clock = fixed_mode->clock;
> >  	}
> >  
> > +	if (intel_dp->upfront_link_train && !intel_dp->upfront_done) 
> > {
> > +		bool do_upfront_link_train;
> > +		/* Do not do upfront link train, if it is a
> > compliance
> > +		 * request
> > +		 */
> > +		do_upfront_link_train = !intel_dp->upfront_done &&
> > +			(intel_dp->compliance_test_type !=
> > +			 DP_TEST_LINK_TRAINING);
> > +
> > +		if (do_upfront_link_train)
> > +			intel_dp->upfront_done =
> > intel_dp_upfront_link_train(intel_dp);
> > +	}
> > +
> >  	max_link_clock = intel_dp_max_link_rate(intel_dp);
> >  	max_lanes = intel_dp_max_lane_count(intel_dp);
> >  
> > @@ -1256,60 +1501,6 @@ intel_dp_aux_init(struct intel_dp *intel_dp,
> > struct intel_connector *connector)
> >  	intel_dp->aux.transfer = intel_dp_aux_transfer;
> >  }
> >  
> > -static int
> > -intel_dp_sink_rates(struct intel_dp *intel_dp, const int
> > **sink_rates)
> > -{
> > -	if (intel_dp->num_sink_rates) {
> > -		*sink_rates = intel_dp->sink_rates;
> > -		return intel_dp->num_sink_rates;
> > -	}
> > -
> > -	*sink_rates = default_rates;
> > -
> > -	return (intel_dp_max_link_bw(intel_dp) >> 3) + 1;
> > -}
> > -
> > -bool intel_dp_source_supports_hbr2(struct intel_dp *intel_dp)
> > -{
> > -	struct intel_digital_port *dig_port =
> > dp_to_dig_port(intel_dp);
> > -	struct drm_device *dev = dig_port->base.base.dev;
> > -
> > -	/* WaDisableHBR2:skl */
> > -	if (IS_SKL_REVID(dev, 0, SKL_REVID_B0))
> > -		return false;
> > -
> > -	if ((IS_HASWELL(dev) && !IS_HSW_ULX(dev)) ||
> > IS_BROADWELL(dev) ||
> > -	    (INTEL_INFO(dev)->gen >= 9))
> > -		return true;
> > -	else
> > -		return false;
> > -}
> > -
> > -static int
> > -intel_dp_source_rates(struct intel_dp *intel_dp, const int
> > **source_rates)
> > -{
> > -	struct intel_digital_port *dig_port =
> > dp_to_dig_port(intel_dp);
> > -	struct drm_device *dev = dig_port->base.base.dev;
> > -	int size;
> > -
> > -	if (IS_BROXTON(dev)) {
> > -		*source_rates = bxt_rates;
> > -		size = ARRAY_SIZE(bxt_rates);
> > -	} else if (IS_SKYLAKE(dev) || IS_KABYLAKE(dev)) {
> > -		*source_rates = skl_rates;
> > -		size = ARRAY_SIZE(skl_rates);
> > -	} else {
> > -		*source_rates = default_rates;
> > -		size = ARRAY_SIZE(default_rates);
> > -	}
> > -
> > -	/* This depends on the fact that 5.4 is last value in the
> > array */
> > -	if (!intel_dp_source_supports_hbr2(intel_dp))
> > -		size--;
> > -
> > -	return size;
> > -}
> > -
> >  static void
> >  intel_dp_set_clock(struct intel_encoder *encoder,
> >  		   struct intel_crtc_state *pipe_config)
> > @@ -1343,42 +1534,6 @@ intel_dp_set_clock(struct intel_encoder
> > *encoder,
> >  	}
> >  }
> >  
> > -static int intersect_rates(const int *source_rates, int source_len,
> > -			   const int *sink_rates, int sink_len,
> > -			   int *common_rates)
> > -{
> > -	int i = 0, j = 0, k = 0;
> > -
> > -	while (i < source_len && j < sink_len) {
> > -		if (source_rates[i] == sink_rates[j]) {
> > -			if (WARN_ON(k >= DP_MAX_SUPPORTED_RATES))
> > -				return k;
> > -			common_rates[k] = source_rates[i];
> > -			++k;
> > -			++i;
> > -			++j;
> > -		} else if (source_rates[i] < sink_rates[j]) {
> > -			++i;
> > -		} else {
> > -			++j;
> > -		}
> > -	}
> > -	return k;
> > -}
> > -
> > -static int intel_dp_common_rates(struct intel_dp *intel_dp,
> > -				 int *common_rates)
> > -{
> > -	const int *source_rates, *sink_rates;
> > -	int source_len, sink_len;
> > -
> > -	sink_len = intel_dp_sink_rates(intel_dp, &sink_rates);
> > -	source_len = intel_dp_source_rates(intel_dp, &source_rates);
> > -
> > -	return intersect_rates(source_rates, source_len,
> > -			       sink_rates, sink_len,
> > -			       common_rates);
> > -}
> >  
> >  static void snprintf_int_array(char *str, size_t len,
> >  			       const int *array, int nelem)
> > @@ -1436,6 +1591,9 @@ intel_dp_max_link_rate(struct intel_dp
> > *intel_dp)
> >  	int rates[DP_MAX_SUPPORTED_RATES] = {};
> >  	int len;
> >  
> > +	if (intel_dp->max_link_rate_upfront)
> > +		return intel_dp->max_link_rate_upfront;
> > +
> >  	len = intel_dp_common_rates(intel_dp, rates);
> >  	if (WARN_ON(len <= 0))
> >  		return 162000;
> > @@ -1488,7 +1646,7 @@ intel_dp_compute_config(struct intel_encoder
> > *encoder,
> >  	enum port port = dp_to_dig_port(intel_dp)->port;
> >  	struct intel_crtc *intel_crtc = to_intel_crtc(pipe_config-
> > >base.crtc);
> >  	struct intel_connector *intel_connector = intel_dp-
> > >attached_connector;
> > -	int lane_count, clock;
> > +	int lane_count, clock = 0;
> >  	int min_lane_count = 1;
> >  	int max_lane_count = intel_dp_max_lane_count(intel_dp);
> >  	/* Conveniently, the link BW constants become indices with a
> > shift...*/
> > @@ -1567,11 +1725,24 @@ intel_dp_compute_config(struct intel_encoder
> > *encoder,
> >  	for (; bpp >= 6*3; bpp -= 2*3) {
> >  		mode_rate = intel_dp_link_required(adjusted_mode-
> > >crtc_clock,
> >  						   bpp);
> > +		if (!is_edp(intel_dp) && intel_dp->upfront_done) {
> > +			clock = max_clock;
> > +			lane_count = intel_dp->max_lanes_upfront;
> > +			link_clock = intel_dp-
> > >max_link_rate_upfront;
> > +			link_avail =
> > intel_dp_max_data_rate(link_clock,
> > +							    lane_cou
> > nt);
> > +			mode_rate =
> > intel_dp_link_required(adjusted_mode->crtc_clock,
> > +							   bpp);
> > +			if (mode_rate <= link_avail)
> > +				goto found;
> > +			else
> > +				continue;
> > +		}
> > +
> >  		for (clock = max_clock; clock >= max_clock; clock--)
> > {
> >  			for (lane_count = max_lane_count;
> >  			     lane_count >= min_lane_count;
> >  			     lane_count >>= 1) {
> > -
> >  				link_clock = common_rates[clock];
> >  				link_avail =
> > intel_dp_max_data_rate(link_clock,
> >  								    
> > lane_count);
> > @@ -1600,7 +1771,6 @@ found:
> >  	}
> >  
> >  	pipe_config->lane_count = lane_count;
> > -
> >  	pipe_config->pipe_bpp = bpp;
> >  	pipe_config->port_clock = common_rates[clock];
> >  
> > @@ -4284,7 +4454,7 @@ intel_dp_long_pulse(struct intel_connector
> > *intel_connector)
> >  	struct drm_device *dev = connector->dev;
> >  	enum drm_connector_status status;
> >  	enum intel_display_power_domain power_domain;
> > -	u8 sink_irq_vector = 0;
> > +	u8 sink_irq_vector;
> >  
> >  	power_domain =
> > intel_display_port_aux_power_domain(intel_encoder);
> >  	intel_display_power_get(to_i915(dev), power_domain);
> > @@ -4377,9 +4547,12 @@ intel_dp_long_pulse(struct intel_connector
> > *intel_connector)
> >  	}
> >  
> >  out:
> > -	if ((status != connector_status_connected) &&
> > -	    (intel_dp->is_mst == false))
> > +	if (status != connector_status_connected) {
> >  		intel_dp_unset_edid(intel_dp);
> > +		intel_dp->upfront_done = false;
> > +		intel_dp->max_lanes_upfront = 0;
> > +		intel_dp->max_link_rate_upfront = 0;
> > +	}
> >  
> >  	intel_display_power_put(to_i915(dev), power_domain);
> >  	return;
> > @@ -5623,6 +5796,13 @@ intel_dp_init_connector(struct
> > intel_digital_port *intel_dig_port,
> >  	if (type == DRM_MODE_CONNECTOR_eDP)
> >  		intel_encoder->type = INTEL_OUTPUT_EDP;
> >  
> > +	/* Initialize upfront link training vfunc for DP */
> > +	if (intel_encoder->type != INTEL_OUTPUT_EDP) {
> > +		if (IS_BROXTON(dev_priv) || IS_SKYLAKE(dev_priv) ||
> > +		    IS_BROADWELL(dev_priv) || IS_HASWELL(dev_priv))
> > +			intel_dp->upfront_link_train =
> > intel_ddi_link_train;
> > +	}
> > +
> >  	/* eDP only on port B and/or C on vlv/chv */
> >  	if (WARN_ON((IS_VALLEYVIEW(dev) || IS_CHERRYVIEW(dev)) &&
> >  		    is_edp(intel_dp) && port != PORT_B && port !=
> > PORT_C))
> > diff --git a/drivers/gpu/drm/i915/intel_dp_link_training.c
> > b/drivers/gpu/drm/i915/intel_dp_link_training.c
> > index f1e08f0..b6f380b 100644
> > --- a/drivers/gpu/drm/i915/intel_dp_link_training.c
> > +++ b/drivers/gpu/drm/i915/intel_dp_link_training.c
> > @@ -304,7 +304,6 @@
> > intel_dp_link_training_channel_equalization(struct intel_dp
> > *intel_dp)
> >  	intel_dp_set_idle_link_train(intel_dp);
> >  
> >  	return intel_dp->channel_eq_status;
> > -
> >  }
> >  
> >  void intel_dp_stop_link_train(struct intel_dp *intel_dp)
> > diff --git a/drivers/gpu/drm/i915/intel_drv.h
> > b/drivers/gpu/drm/i915/intel_drv.h
> > index c571baf..a2bbf68 100644
> > --- a/drivers/gpu/drm/i915/intel_drv.h
> > +++ b/drivers/gpu/drm/i915/intel_drv.h
> > @@ -882,6 +882,12 @@ struct intel_dp {
> >  	enum hdmi_force_audio force_audio;
> >  	bool limited_color_range;
> >  	bool color_range_auto;
> > +
> > +	/* Upfront link train parameters */
> > +	int max_link_rate_upfront;
> > +	uint8_t max_lanes_upfront;
> > +	bool upfront_done;
> > +
> >  	uint8_t dpcd[DP_RECEIVER_CAP_SIZE];
> >  	uint8_t psr_dpcd[EDP_PSR_RECEIVER_CAP_SIZE];
> >  	uint8_t downstream_ports[DP_MAX_DOWNSTREAM_PORTS];
> > @@ -939,6 +945,11 @@ struct intel_dp {
> >  	/* This is called before a link training is starterd */
> >  	void (*prepare_link_retrain)(struct intel_dp *intel_dp);
> >  
> > +	/* For Upfront link training */
> > +	bool (*upfront_link_train)(struct intel_dp *intel_dp, int
> > clock,
> > +				   uint8_t lane_count, bool
> > link_mst,
> > +				   bool is_upfront);
> > +
> >  	/* Displayport compliance testing */
> >  	unsigned long compliance_test_type;
> >  	unsigned long compliance_test_data;
> > @@ -1161,7 +1172,8 @@ void intel_ddi_clock_get(struct intel_encoder
> > *encoder,
> >  void intel_ddi_set_vc_payload_alloc(struct drm_crtc *crtc, bool
> > state);
> >  uint32_t ddi_signal_levels(struct intel_dp *intel_dp);
> >  bool intel_ddi_link_train(struct intel_dp *intel_dp, int
> > max_link_rate,
> > -			  uint8_t max_lane_count, bool link_mst);
> > +			  uint8_t max_lane_count, bool link_mst,
> > +			  bool is_upfront);
> >  struct intel_shared_dpll *intel_ddi_get_link_dpll(struct intel_dp
> > *intel_dp,
> >  						  int clock);
> >  unsigned int intel_fb_align_height(struct drm_device *dev,
> -- 
> Mika Kahola - Intel OTC
> 


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