diff mbox

[v3,5/5] drm/i915/dp/mst: Add support for upfront link training for DP MST

Message ID 1473815299-26961-6-git-send-email-manasi.d.navare@intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Navare, Manasi Sept. 14, 2016, 1:08 a.m. UTC
From: Jim Bride <jim.bride@linux.intel.com>

Add upfront link training to intel_dp_mst_mode_valid() so that we know
topology constraints before we validate the legality of modes to be
checked.

v3:
* Reset the upfront values but dont unset the EDID for MST. (Manasi)
v2:
* Rebased on new revision of link training patch. (Manasi)

Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
Signed-off-by: Jim Bride <jim.bride@linux.intel.com>
---
 drivers/gpu/drm/i915/intel_dp.c     | 15 ++++----
 drivers/gpu/drm/i915/intel_dp_mst.c | 74 +++++++++++++++++++++++++++----------
 drivers/gpu/drm/i915/intel_drv.h    |  3 ++
 3 files changed, 64 insertions(+), 28 deletions(-)

Comments

Dhinakaran Pandiyan Sept. 15, 2016, 5:48 p.m. UTC | #1
On Tue, 2016-09-13 at 18:08 -0700, Manasi Navare wrote:
> From: Jim Bride <jim.bride@linux.intel.com>

> 

> Add upfront link training to intel_dp_mst_mode_valid() so that we know

> topology constraints before we validate the legality of modes to be

> checked.

> 


The patch seems to do a lot more things than just what is described
here. I guess, it would be better to split this into multiple patches or
at least provide adequate description here.

> v3:

> * Reset the upfront values but dont unset the EDID for MST. (Manasi)

> v2:

> * Rebased on new revision of link training patch. (Manasi)

> 

> Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>

> Signed-off-by: Jim Bride <jim.bride@linux.intel.com>

> ---

>  drivers/gpu/drm/i915/intel_dp.c     | 15 ++++----

>  drivers/gpu/drm/i915/intel_dp_mst.c | 74 +++++++++++++++++++++++++++----------

>  drivers/gpu/drm/i915/intel_drv.h    |  3 ++

>  3 files changed, 64 insertions(+), 28 deletions(-)

> 

> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c

> index 9042d28..635830e 100644

> --- a/drivers/gpu/drm/i915/intel_dp.c

> +++ b/drivers/gpu/drm/i915/intel_dp.c

> @@ -131,7 +131,7 @@ static void vlv_steal_power_sequencer(struct drm_device *dev,

>  				      enum pipe pipe);

>  static void intel_dp_unset_edid(struct intel_dp *intel_dp);

>  

> -static int

> +int

>  intel_dp_max_link_bw(struct intel_dp  *intel_dp)

>  {

>  	int max_link_bw = intel_dp->dpcd[DP_MAX_LINK_RATE];

> @@ -150,7 +150,7 @@ intel_dp_max_link_bw(struct intel_dp  *intel_dp)

>  	return max_link_bw;

>  }

>  

> -static u8 intel_dp_max_lane_count(struct intel_dp *intel_dp)

> +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 temp, source_max, sink_max;

> @@ -296,8 +296,7 @@ static int intersect_rates(const int *source_rates, int source_len,

>  	return k;

>  }

>  

> -static int intel_dp_common_rates(struct intel_dp *intel_dp,

> -				 int *common_rates)

> +int intel_dp_common_rates(struct intel_dp *intel_dp, int *common_rates)

>  {

>  	const int *source_rates, *sink_rates;

>  	int source_len, sink_len;

> @@ -321,7 +320,7 @@ static int intel_dp_common_rates(struct intel_dp *intel_dp,

>  			       common_rates);

>  }

>  

> -static bool intel_dp_upfront_link_train(struct intel_dp *intel_dp)

> +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;

> @@ -4545,12 +4544,12 @@ intel_dp_long_pulse(struct intel_connector *intel_connector)

>  	}

>  

>  out:

> -	if ((status != connector_status_connected) &&

> -	    (intel_dp->is_mst == false)) {

> -		intel_dp_unset_edid(intel_dp);

> +	if (status != connector_status_connected) {

>  		intel_dp->upfront_done = false;

>  		intel_dp->max_lanes_upfront = 0;

>  		intel_dp->max_link_rate_upfront = 0;

> +		if (intel_dp->is_mst == false)

> +			intel_dp_unset_edid(intel_dp);

>  	}

>  

>  	intel_display_power_put(to_i915(dev), power_domain);

> diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c

> index 54a9d76..98d45a4 100644

> --- a/drivers/gpu/drm/i915/intel_dp_mst.c

> +++ b/drivers/gpu/drm/i915/intel_dp_mst.c

> @@ -41,21 +41,30 @@ static bool intel_dp_mst_compute_config(struct intel_encoder *encoder,

>  	int bpp;

>  	int lane_count, slots;

>  	const struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode;

> -	int mst_pbn;

> +	int mst_pbn, common_len;

> +	int common_rates[DP_MAX_SUPPORTED_RATES] = {};

>  

>  	pipe_config->dp_encoder_is_mst = true;

>  	pipe_config->has_pch_encoder = false;

> -	bpp = 24;

> +

>  	/*

> -	 * for MST we always configure max link bw - the spec doesn't

> -	 * seem to suggest we should do otherwise.

> +	 * For MST we always configure for the maximum trainable link bw -

> +	 * the spec doesn't seem to suggest we should do otherwise.  The

> +	 * calls to intel_dp_max_lane_count() and intel_dp_common_rates()

> +	 * both take successful upfront link training into account, and

> +	 * return the DisplayPort max supported values in the event that

> +	 * upfront link training was not done.

>  	 */

> -	lane_count = drm_dp_max_lane_count(intel_dp->dpcd);

> +	lane_count = intel_dp_max_lane_count(intel_dp);

>  

>  	pipe_config->lane_count = lane_count;

>  

> -	pipe_config->pipe_bpp = 24;

> -	pipe_config->port_clock = intel_dp_max_link_rate(intel_dp);

> +	pipe_config->pipe_bpp = bpp = 24;

> +	common_len = intel_dp_common_rates(intel_dp, common_rates);

> +	pipe_config->port_clock = common_rates[common_len - 1];

> +

> +	DRM_DEBUG_KMS("DP MST link configured for %d lanes @ %d.\n",

> +		      pipe_config->lane_count, pipe_config->port_clock);

>  

>  	state = pipe_config->base.state;

>  

> @@ -137,6 +146,8 @@ static void intel_mst_pre_enable_dp(struct intel_encoder *encoder,

>  	enum port port = intel_dig_port->port;

>  	struct intel_connector *connector =

>  		to_intel_connector(conn_state->connector);

> +	struct intel_shared_dpll *pll = pipe_config->shared_dpll;

> +	struct intel_shared_dpll_config tmp_pll_config;

>  	int ret;

>  	uint32_t temp;

>  	int slots;

> @@ -150,21 +161,23 @@ static void intel_mst_pre_enable_dp(struct intel_encoder *encoder,

>  	DRM_DEBUG_KMS("%d\n", intel_dp->active_mst_links);

>  

>  	if (intel_dp->active_mst_links == 0) {

> -		intel_ddi_clk_select(&intel_dig_port->base,

> -				     pipe_config->shared_dpll);

> -

> -		intel_prepare_dp_ddi_buffers(&intel_dig_port->base);

> -		intel_dp_set_link_params(intel_dp,

> -					 pipe_config->port_clock,

> -					 pipe_config->lane_count,

> -					 true);

> -

> -		intel_ddi_init_dp_buf_reg(&intel_dig_port->base);

>  

> -		intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON);

> +		/* Disable the PLL since we need to acquire the PLL

> +		 * based on the link rate in the link training sequence

> +		 */

> +		tmp_pll_config = pll->config;

> +		pll->funcs.disable(dev_priv, pll);

> +		pll->config.crtc_mask = 0;

> +

> +		/* If Link Training fails, send a uevent to generate a

> +		 *hotplug

> +		 */

> +		if (!(intel_ddi_link_train(intel_dp, pipe_config->port_clock,

> +					   pipe_config->lane_count, true,

> +					   false)))

> +			drm_kms_helper_hotplug_event(encoder->base.dev);

> +		pll->config = tmp_pll_config;

>  

> -		intel_dp_start_link_train(intel_dp);

> -		intel_dp_stop_link_train(intel_dp);

>  	}

>  

>  	ret = drm_dp_mst_allocate_vcpi(&intel_dp->mst_mgr,

> @@ -336,6 +349,27 @@ intel_dp_mst_mode_valid(struct drm_connector *connector,

>  			struct drm_display_mode *mode)

>  {

>  	int max_dotclk = to_i915(connector->dev)->max_dotclk_freq;

> +	struct intel_connector *intel_connector = to_intel_connector(connector);

> +	struct intel_dp *intel_dp = intel_connector->mst_port;

> +

> +	if (intel_dp->upfront_link_train && !intel_dp->upfront_done) {

> +		bool do_upfront_link_train;

> +

> +		do_upfront_link_train = 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);

> +			if (intel_dp->upfront_done) {

> +				DRM_DEBUG_KMS("MST upfront trained at "

> +					      "%d lanes @ %d.",

> +					      intel_dp->max_lanes_upfront,

> +					      intel_dp->max_link_rate_upfront);

> +			} else

> +				DRM_DEBUG_KMS("MST upfront link training "

> +					      "failed.");

> +		}

> +	}

>  

>  	/* TODO - validate mode against available PBN for link */

>  	if (mode->clock < 10000)

> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h

> index fc2f1bc..b4bc002 100644

> --- a/drivers/gpu/drm/i915/intel_drv.h

> +++ b/drivers/gpu/drm/i915/intel_drv.h

> @@ -1416,6 +1416,7 @@ void intel_edp_panel_off(struct intel_dp *intel_dp);

>  void intel_dp_add_properties(struct intel_dp *intel_dp, struct drm_connector *connector);

>  void intel_dp_mst_suspend(struct drm_device *dev);

>  void intel_dp_mst_resume(struct drm_device *dev);

> +u8 intel_dp_max_lane_count(struct intel_dp *intel_dp);

>  int intel_dp_max_link_rate(struct intel_dp *intel_dp);

>  int intel_dp_link_rate_index(struct intel_dp *intel_dp, int *common_rates,

>  			     int link_rate);

> @@ -1446,6 +1447,8 @@ intel_dp_pre_emphasis_max(struct intel_dp *intel_dp, uint8_t voltage_swing);

>  void intel_dp_compute_rate(struct intel_dp *intel_dp, int port_clock,

>  			   uint8_t *link_bw, uint8_t *rate_select);

>  bool intel_dp_source_supports_hbr2(struct intel_dp *intel_dp);

> +int intel_dp_common_rates(struct intel_dp *intel_dp, int *common_rates);

> +bool intel_dp_upfront_link_train(struct intel_dp *intel_dp);

>  bool

>  intel_dp_get_link_status(struct intel_dp *intel_dp, uint8_t link_status[DP_LINK_STATUS_SIZE]);

>
Navare, Manasi Sept. 15, 2016, 7:25 p.m. UTC | #2
On Thu, Sep 15, 2016 at 10:48:17AM -0700, Pandiyan, Dhinakaran wrote:
> On Tue, 2016-09-13 at 18:08 -0700, Manasi Navare wrote:
> > From: Jim Bride <jim.bride@linux.intel.com>
> > 
> > Add upfront link training to intel_dp_mst_mode_valid() so that we know
> > topology constraints before we validate the legality of modes to be
> > checked.
> > 
> 
> The patch seems to do a lot more things than just what is described
> here. I guess, it would be better to split this into multiple patches or
> at least provide adequate description here.
> 

I think the only other thing its doing is making some functions
non static so they can be used for MST upfront enabling.
But I think that can be in the same patch since it is done in order
to enable upfront for MST.
Jim, any thoughts?


> > v3:
> > * Reset the upfront values but dont unset the EDID for MST. (Manasi)
> > v2:
> > * Rebased on new revision of link training patch. (Manasi)
> > 
> > Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
> > Signed-off-by: Jim Bride <jim.bride@linux.intel.com>
> > ---
> >  drivers/gpu/drm/i915/intel_dp.c     | 15 ++++----
> >  drivers/gpu/drm/i915/intel_dp_mst.c | 74 +++++++++++++++++++++++++++----------
> >  drivers/gpu/drm/i915/intel_drv.h    |  3 ++
> >  3 files changed, 64 insertions(+), 28 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> > index 9042d28..635830e 100644
> > --- a/drivers/gpu/drm/i915/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/intel_dp.c
> > @@ -131,7 +131,7 @@ static void vlv_steal_power_sequencer(struct drm_device *dev,
> >  				      enum pipe pipe);
> >  static void intel_dp_unset_edid(struct intel_dp *intel_dp);
> >  
> > -static int
> > +int
> >  intel_dp_max_link_bw(struct intel_dp  *intel_dp)
> >  {
> >  	int max_link_bw = intel_dp->dpcd[DP_MAX_LINK_RATE];
> > @@ -150,7 +150,7 @@ intel_dp_max_link_bw(struct intel_dp  *intel_dp)
> >  	return max_link_bw;
> >  }
> >  
> > -static u8 intel_dp_max_lane_count(struct intel_dp *intel_dp)
> > +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 temp, source_max, sink_max;
> > @@ -296,8 +296,7 @@ static int intersect_rates(const int *source_rates, int source_len,
> >  	return k;
> >  }
> >  
> > -static int intel_dp_common_rates(struct intel_dp *intel_dp,
> > -				 int *common_rates)
> > +int intel_dp_common_rates(struct intel_dp *intel_dp, int *common_rates)
> >  {
> >  	const int *source_rates, *sink_rates;
> >  	int source_len, sink_len;
> > @@ -321,7 +320,7 @@ static int intel_dp_common_rates(struct intel_dp *intel_dp,
> >  			       common_rates);
> >  }
> >  
> > -static bool intel_dp_upfront_link_train(struct intel_dp *intel_dp)
> > +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;
> > @@ -4545,12 +4544,12 @@ intel_dp_long_pulse(struct intel_connector *intel_connector)
> >  	}
> >  
> >  out:
> > -	if ((status != connector_status_connected) &&
> > -	    (intel_dp->is_mst == false)) {
> > -		intel_dp_unset_edid(intel_dp);
> > +	if (status != connector_status_connected) {
> >  		intel_dp->upfront_done = false;
> >  		intel_dp->max_lanes_upfront = 0;
> >  		intel_dp->max_link_rate_upfront = 0;
> > +		if (intel_dp->is_mst == false)
> > +			intel_dp_unset_edid(intel_dp);
> >  	}
> >  
> >  	intel_display_power_put(to_i915(dev), power_domain);
> > diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c
> > index 54a9d76..98d45a4 100644
> > --- a/drivers/gpu/drm/i915/intel_dp_mst.c
> > +++ b/drivers/gpu/drm/i915/intel_dp_mst.c
> > @@ -41,21 +41,30 @@ static bool intel_dp_mst_compute_config(struct intel_encoder *encoder,
> >  	int bpp;
> >  	int lane_count, slots;
> >  	const struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode;
> > -	int mst_pbn;
> > +	int mst_pbn, common_len;
> > +	int common_rates[DP_MAX_SUPPORTED_RATES] = {};
> >  
> >  	pipe_config->dp_encoder_is_mst = true;
> >  	pipe_config->has_pch_encoder = false;
> > -	bpp = 24;
> > +
> >  	/*
> > -	 * for MST we always configure max link bw - the spec doesn't
> > -	 * seem to suggest we should do otherwise.
> > +	 * For MST we always configure for the maximum trainable link bw -
> > +	 * the spec doesn't seem to suggest we should do otherwise.  The
> > +	 * calls to intel_dp_max_lane_count() and intel_dp_common_rates()
> > +	 * both take successful upfront link training into account, and
> > +	 * return the DisplayPort max supported values in the event that
> > +	 * upfront link training was not done.
> >  	 */
> > -	lane_count = drm_dp_max_lane_count(intel_dp->dpcd);
> > +	lane_count = intel_dp_max_lane_count(intel_dp);
> >  
> >  	pipe_config->lane_count = lane_count;
> >  
> > -	pipe_config->pipe_bpp = 24;
> > -	pipe_config->port_clock = intel_dp_max_link_rate(intel_dp);
> > +	pipe_config->pipe_bpp = bpp = 24;
> > +	common_len = intel_dp_common_rates(intel_dp, common_rates);
> > +	pipe_config->port_clock = common_rates[common_len - 1];
> > +
> > +	DRM_DEBUG_KMS("DP MST link configured for %d lanes @ %d.\n",
> > +		      pipe_config->lane_count, pipe_config->port_clock);
> >  
> >  	state = pipe_config->base.state;
> >  
> > @@ -137,6 +146,8 @@ static void intel_mst_pre_enable_dp(struct intel_encoder *encoder,
> >  	enum port port = intel_dig_port->port;
> >  	struct intel_connector *connector =
> >  		to_intel_connector(conn_state->connector);
> > +	struct intel_shared_dpll *pll = pipe_config->shared_dpll;
> > +	struct intel_shared_dpll_config tmp_pll_config;
> >  	int ret;
> >  	uint32_t temp;
> >  	int slots;
> > @@ -150,21 +161,23 @@ static void intel_mst_pre_enable_dp(struct intel_encoder *encoder,
> >  	DRM_DEBUG_KMS("%d\n", intel_dp->active_mst_links);
> >  
> >  	if (intel_dp->active_mst_links == 0) {
> > -		intel_ddi_clk_select(&intel_dig_port->base,
> > -				     pipe_config->shared_dpll);
> > -
> > -		intel_prepare_dp_ddi_buffers(&intel_dig_port->base);
> > -		intel_dp_set_link_params(intel_dp,
> > -					 pipe_config->port_clock,
> > -					 pipe_config->lane_count,
> > -					 true);
> > -
> > -		intel_ddi_init_dp_buf_reg(&intel_dig_port->base);
> >  
> > -		intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON);
> > +		/* Disable the PLL since we need to acquire the PLL
> > +		 * based on the link rate in the link training sequence
> > +		 */
> > +		tmp_pll_config = pll->config;
> > +		pll->funcs.disable(dev_priv, pll);
> > +		pll->config.crtc_mask = 0;
> > +
> > +		/* If Link Training fails, send a uevent to generate a
> > +		 *hotplug
> > +		 */
> > +		if (!(intel_ddi_link_train(intel_dp, pipe_config->port_clock,
> > +					   pipe_config->lane_count, true,
> > +					   false)))
> > +			drm_kms_helper_hotplug_event(encoder->base.dev);
> > +		pll->config = tmp_pll_config;
> >  
> > -		intel_dp_start_link_train(intel_dp);
> > -		intel_dp_stop_link_train(intel_dp);
> >  	}
> >  
> >  	ret = drm_dp_mst_allocate_vcpi(&intel_dp->mst_mgr,
> > @@ -336,6 +349,27 @@ intel_dp_mst_mode_valid(struct drm_connector *connector,
> >  			struct drm_display_mode *mode)
> >  {
> >  	int max_dotclk = to_i915(connector->dev)->max_dotclk_freq;
> > +	struct intel_connector *intel_connector = to_intel_connector(connector);
> > +	struct intel_dp *intel_dp = intel_connector->mst_port;
> > +
> > +	if (intel_dp->upfront_link_train && !intel_dp->upfront_done) {
> > +		bool do_upfront_link_train;
> > +
> > +		do_upfront_link_train = 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);
> > +			if (intel_dp->upfront_done) {
> > +				DRM_DEBUG_KMS("MST upfront trained at "
> > +					      "%d lanes @ %d.",
> > +					      intel_dp->max_lanes_upfront,
> > +					      intel_dp->max_link_rate_upfront);
> > +			} else
> > +				DRM_DEBUG_KMS("MST upfront link training "
> > +					      "failed.");
> > +		}
> > +	}
> >  
> >  	/* TODO - validate mode against available PBN for link */
> >  	if (mode->clock < 10000)
> > diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> > index fc2f1bc..b4bc002 100644
> > --- a/drivers/gpu/drm/i915/intel_drv.h
> > +++ b/drivers/gpu/drm/i915/intel_drv.h
> > @@ -1416,6 +1416,7 @@ void intel_edp_panel_off(struct intel_dp *intel_dp);
> >  void intel_dp_add_properties(struct intel_dp *intel_dp, struct drm_connector *connector);
> >  void intel_dp_mst_suspend(struct drm_device *dev);
> >  void intel_dp_mst_resume(struct drm_device *dev);
> > +u8 intel_dp_max_lane_count(struct intel_dp *intel_dp);
> >  int intel_dp_max_link_rate(struct intel_dp *intel_dp);
> >  int intel_dp_link_rate_index(struct intel_dp *intel_dp, int *common_rates,
> >  			     int link_rate);
> > @@ -1446,6 +1447,8 @@ intel_dp_pre_emphasis_max(struct intel_dp *intel_dp, uint8_t voltage_swing);
> >  void intel_dp_compute_rate(struct intel_dp *intel_dp, int port_clock,
> >  			   uint8_t *link_bw, uint8_t *rate_select);
> >  bool intel_dp_source_supports_hbr2(struct intel_dp *intel_dp);
> > +int intel_dp_common_rates(struct intel_dp *intel_dp, int *common_rates);
> > +bool intel_dp_upfront_link_train(struct intel_dp *intel_dp);
> >  bool
> >  intel_dp_get_link_status(struct intel_dp *intel_dp, uint8_t link_status[DP_LINK_STATUS_SIZE]);
> >  
>
jim.bride@linux.intel.com Sept. 19, 2016, 5:03 p.m. UTC | #3
On Thu, Sep 15, 2016 at 12:25:51PM -0700, Manasi Navare wrote:
> On Thu, Sep 15, 2016 at 10:48:17AM -0700, Pandiyan, Dhinakaran wrote:
> > On Tue, 2016-09-13 at 18:08 -0700, Manasi Navare wrote:
> > > From: Jim Bride <jim.bride@linux.intel.com>
> > > 
> > > Add upfront link training to intel_dp_mst_mode_valid() so that we know
> > > topology constraints before we validate the legality of modes to be
> > > checked.
> > > 
> > 
> > The patch seems to do a lot more things than just what is described
> > here. I guess, it would be better to split this into multiple patches or
> > at least provide adequate description here.
> > 
> 
> I think the only other thing its doing is making some functions
> non static so they can be used for MST upfront enabling.
> But I think that can be in the same patch since it is done in order
> to enable upfront for MST.
> Jim, any thoughts?

This is exactly the case.

Jim

> 
> > > v3:
> > > * Reset the upfront values but dont unset the EDID for MST. (Manasi)
> > > v2:
> > > * Rebased on new revision of link training patch. (Manasi)
> > > 
> > > Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
> > > Signed-off-by: Jim Bride <jim.bride@linux.intel.com>
> > > ---
> > >  drivers/gpu/drm/i915/intel_dp.c     | 15 ++++----
> > >  drivers/gpu/drm/i915/intel_dp_mst.c | 74 +++++++++++++++++++++++++++----------
> > >  drivers/gpu/drm/i915/intel_drv.h    |  3 ++
> > >  3 files changed, 64 insertions(+), 28 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> > > index 9042d28..635830e 100644
> > > --- a/drivers/gpu/drm/i915/intel_dp.c
> > > +++ b/drivers/gpu/drm/i915/intel_dp.c
> > > @@ -131,7 +131,7 @@ static void vlv_steal_power_sequencer(struct drm_device *dev,
> > >  				      enum pipe pipe);
> > >  static void intel_dp_unset_edid(struct intel_dp *intel_dp);
> > >  
> > > -static int
> > > +int
> > >  intel_dp_max_link_bw(struct intel_dp  *intel_dp)
> > >  {
> > >  	int max_link_bw = intel_dp->dpcd[DP_MAX_LINK_RATE];
> > > @@ -150,7 +150,7 @@ intel_dp_max_link_bw(struct intel_dp  *intel_dp)
> > >  	return max_link_bw;
> > >  }
> > >  
> > > -static u8 intel_dp_max_lane_count(struct intel_dp *intel_dp)
> > > +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 temp, source_max, sink_max;
> > > @@ -296,8 +296,7 @@ static int intersect_rates(const int *source_rates, int source_len,
> > >  	return k;
> > >  }
> > >  
> > > -static int intel_dp_common_rates(struct intel_dp *intel_dp,
> > > -				 int *common_rates)
> > > +int intel_dp_common_rates(struct intel_dp *intel_dp, int *common_rates)
> > >  {
> > >  	const int *source_rates, *sink_rates;
> > >  	int source_len, sink_len;
> > > @@ -321,7 +320,7 @@ static int intel_dp_common_rates(struct intel_dp *intel_dp,
> > >  			       common_rates);
> > >  }
> > >  
> > > -static bool intel_dp_upfront_link_train(struct intel_dp *intel_dp)
> > > +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;
> > > @@ -4545,12 +4544,12 @@ intel_dp_long_pulse(struct intel_connector *intel_connector)
> > >  	}
> > >  
> > >  out:
> > > -	if ((status != connector_status_connected) &&
> > > -	    (intel_dp->is_mst == false)) {
> > > -		intel_dp_unset_edid(intel_dp);
> > > +	if (status != connector_status_connected) {
> > >  		intel_dp->upfront_done = false;
> > >  		intel_dp->max_lanes_upfront = 0;
> > >  		intel_dp->max_link_rate_upfront = 0;
> > > +		if (intel_dp->is_mst == false)
> > > +			intel_dp_unset_edid(intel_dp);
> > >  	}
> > >  
> > >  	intel_display_power_put(to_i915(dev), power_domain);
> > > diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c
> > > index 54a9d76..98d45a4 100644
> > > --- a/drivers/gpu/drm/i915/intel_dp_mst.c
> > > +++ b/drivers/gpu/drm/i915/intel_dp_mst.c
> > > @@ -41,21 +41,30 @@ static bool intel_dp_mst_compute_config(struct intel_encoder *encoder,
> > >  	int bpp;
> > >  	int lane_count, slots;
> > >  	const struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode;
> > > -	int mst_pbn;
> > > +	int mst_pbn, common_len;
> > > +	int common_rates[DP_MAX_SUPPORTED_RATES] = {};
> > >  
> > >  	pipe_config->dp_encoder_is_mst = true;
> > >  	pipe_config->has_pch_encoder = false;
> > > -	bpp = 24;
> > > +
> > >  	/*
> > > -	 * for MST we always configure max link bw - the spec doesn't
> > > -	 * seem to suggest we should do otherwise.
> > > +	 * For MST we always configure for the maximum trainable link bw -
> > > +	 * the spec doesn't seem to suggest we should do otherwise.  The
> > > +	 * calls to intel_dp_max_lane_count() and intel_dp_common_rates()
> > > +	 * both take successful upfront link training into account, and
> > > +	 * return the DisplayPort max supported values in the event that
> > > +	 * upfront link training was not done.
> > >  	 */
> > > -	lane_count = drm_dp_max_lane_count(intel_dp->dpcd);
> > > +	lane_count = intel_dp_max_lane_count(intel_dp);
> > >  
> > >  	pipe_config->lane_count = lane_count;
> > >  
> > > -	pipe_config->pipe_bpp = 24;
> > > -	pipe_config->port_clock = intel_dp_max_link_rate(intel_dp);
> > > +	pipe_config->pipe_bpp = bpp = 24;
> > > +	common_len = intel_dp_common_rates(intel_dp, common_rates);
> > > +	pipe_config->port_clock = common_rates[common_len - 1];
> > > +
> > > +	DRM_DEBUG_KMS("DP MST link configured for %d lanes @ %d.\n",
> > > +		      pipe_config->lane_count, pipe_config->port_clock);
> > >  
> > >  	state = pipe_config->base.state;
> > >  
> > > @@ -137,6 +146,8 @@ static void intel_mst_pre_enable_dp(struct intel_encoder *encoder,
> > >  	enum port port = intel_dig_port->port;
> > >  	struct intel_connector *connector =
> > >  		to_intel_connector(conn_state->connector);
> > > +	struct intel_shared_dpll *pll = pipe_config->shared_dpll;
> > > +	struct intel_shared_dpll_config tmp_pll_config;
> > >  	int ret;
> > >  	uint32_t temp;
> > >  	int slots;
> > > @@ -150,21 +161,23 @@ static void intel_mst_pre_enable_dp(struct intel_encoder *encoder,
> > >  	DRM_DEBUG_KMS("%d\n", intel_dp->active_mst_links);
> > >  
> > >  	if (intel_dp->active_mst_links == 0) {
> > > -		intel_ddi_clk_select(&intel_dig_port->base,
> > > -				     pipe_config->shared_dpll);
> > > -
> > > -		intel_prepare_dp_ddi_buffers(&intel_dig_port->base);
> > > -		intel_dp_set_link_params(intel_dp,
> > > -					 pipe_config->port_clock,
> > > -					 pipe_config->lane_count,
> > > -					 true);
> > > -
> > > -		intel_ddi_init_dp_buf_reg(&intel_dig_port->base);
> > >  
> > > -		intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON);
> > > +		/* Disable the PLL since we need to acquire the PLL
> > > +		 * based on the link rate in the link training sequence
> > > +		 */
> > > +		tmp_pll_config = pll->config;
> > > +		pll->funcs.disable(dev_priv, pll);
> > > +		pll->config.crtc_mask = 0;
> > > +
> > > +		/* If Link Training fails, send a uevent to generate a
> > > +		 *hotplug
> > > +		 */
> > > +		if (!(intel_ddi_link_train(intel_dp, pipe_config->port_clock,
> > > +					   pipe_config->lane_count, true,
> > > +					   false)))
> > > +			drm_kms_helper_hotplug_event(encoder->base.dev);
> > > +		pll->config = tmp_pll_config;
> > >  
> > > -		intel_dp_start_link_train(intel_dp);
> > > -		intel_dp_stop_link_train(intel_dp);
> > >  	}
> > >  
> > >  	ret = drm_dp_mst_allocate_vcpi(&intel_dp->mst_mgr,
> > > @@ -336,6 +349,27 @@ intel_dp_mst_mode_valid(struct drm_connector *connector,
> > >  			struct drm_display_mode *mode)
> > >  {
> > >  	int max_dotclk = to_i915(connector->dev)->max_dotclk_freq;
> > > +	struct intel_connector *intel_connector = to_intel_connector(connector);
> > > +	struct intel_dp *intel_dp = intel_connector->mst_port;
> > > +
> > > +	if (intel_dp->upfront_link_train && !intel_dp->upfront_done) {
> > > +		bool do_upfront_link_train;
> > > +
> > > +		do_upfront_link_train = 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);
> > > +			if (intel_dp->upfront_done) {
> > > +				DRM_DEBUG_KMS("MST upfront trained at "
> > > +					      "%d lanes @ %d.",
> > > +					      intel_dp->max_lanes_upfront,
> > > +					      intel_dp->max_link_rate_upfront);
> > > +			} else
> > > +				DRM_DEBUG_KMS("MST upfront link training "
> > > +					      "failed.");
> > > +		}
> > > +	}
> > >  
> > >  	/* TODO - validate mode against available PBN for link */
> > >  	if (mode->clock < 10000)
> > > diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> > > index fc2f1bc..b4bc002 100644
> > > --- a/drivers/gpu/drm/i915/intel_drv.h
> > > +++ b/drivers/gpu/drm/i915/intel_drv.h
> > > @@ -1416,6 +1416,7 @@ void intel_edp_panel_off(struct intel_dp *intel_dp);
> > >  void intel_dp_add_properties(struct intel_dp *intel_dp, struct drm_connector *connector);
> > >  void intel_dp_mst_suspend(struct drm_device *dev);
> > >  void intel_dp_mst_resume(struct drm_device *dev);
> > > +u8 intel_dp_max_lane_count(struct intel_dp *intel_dp);
> > >  int intel_dp_max_link_rate(struct intel_dp *intel_dp);
> > >  int intel_dp_link_rate_index(struct intel_dp *intel_dp, int *common_rates,
> > >  			     int link_rate);
> > > @@ -1446,6 +1447,8 @@ intel_dp_pre_emphasis_max(struct intel_dp *intel_dp, uint8_t voltage_swing);
> > >  void intel_dp_compute_rate(struct intel_dp *intel_dp, int port_clock,
> > >  			   uint8_t *link_bw, uint8_t *rate_select);
> > >  bool intel_dp_source_supports_hbr2(struct intel_dp *intel_dp);
> > > +int intel_dp_common_rates(struct intel_dp *intel_dp, int *common_rates);
> > > +bool intel_dp_upfront_link_train(struct intel_dp *intel_dp);
> > >  bool
> > >  intel_dp_get_link_status(struct intel_dp *intel_dp, uint8_t link_status[DP_LINK_STATUS_SIZE]);
> > >  
> > 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
Navare, Manasi Sept. 19, 2016, 5:22 p.m. UTC | #4
On Mon, Sep 19, 2016 at 10:03:29AM -0700, Jim Bride wrote:
> On Thu, Sep 15, 2016 at 12:25:51PM -0700, Manasi Navare wrote:
> > On Thu, Sep 15, 2016 at 10:48:17AM -0700, Pandiyan, Dhinakaran wrote:
> > > On Tue, 2016-09-13 at 18:08 -0700, Manasi Navare wrote:
> > > > From: Jim Bride <jim.bride@linux.intel.com>
> > > > 
> > > > Add upfront link training to intel_dp_mst_mode_valid() so that we know
> > > > topology constraints before we validate the legality of modes to be
> > > > checked.
> > > > 
> > > 
> > > The patch seems to do a lot more things than just what is described
> > > here. I guess, it would be better to split this into multiple patches or
> > > at least provide adequate description here.
> > > 
> > 
> > I think the only other thing its doing is making some functions
> > non static so they can be used for MST upfront enabling.
> > But I think that can be in the same patch since it is done in order
> > to enable upfront for MST.
> > Jim, any thoughts?
> 
> This is exactly the case.
> 
> Jim

I have already resubmitted a newer version of the patch with the description
more coherent to what the patch is doing.

Manasi
> 
> > 
> > > > v3:
> > > > * Reset the upfront values but dont unset the EDID for MST. (Manasi)
> > > > v2:
> > > > * Rebased on new revision of link training patch. (Manasi)
> > > > 
> > > > Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
> > > > Signed-off-by: Jim Bride <jim.bride@linux.intel.com>
> > > > ---
> > > >  drivers/gpu/drm/i915/intel_dp.c     | 15 ++++----
> > > >  drivers/gpu/drm/i915/intel_dp_mst.c | 74 +++++++++++++++++++++++++++----------
> > > >  drivers/gpu/drm/i915/intel_drv.h    |  3 ++
> > > >  3 files changed, 64 insertions(+), 28 deletions(-)
> > > > 
> > > > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> > > > index 9042d28..635830e 100644
> > > > --- a/drivers/gpu/drm/i915/intel_dp.c
> > > > +++ b/drivers/gpu/drm/i915/intel_dp.c
> > > > @@ -131,7 +131,7 @@ static void vlv_steal_power_sequencer(struct drm_device *dev,
> > > >  				      enum pipe pipe);
> > > >  static void intel_dp_unset_edid(struct intel_dp *intel_dp);
> > > >  
> > > > -static int
> > > > +int
> > > >  intel_dp_max_link_bw(struct intel_dp  *intel_dp)
> > > >  {
> > > >  	int max_link_bw = intel_dp->dpcd[DP_MAX_LINK_RATE];
> > > > @@ -150,7 +150,7 @@ intel_dp_max_link_bw(struct intel_dp  *intel_dp)
> > > >  	return max_link_bw;
> > > >  }
> > > >  
> > > > -static u8 intel_dp_max_lane_count(struct intel_dp *intel_dp)
> > > > +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 temp, source_max, sink_max;
> > > > @@ -296,8 +296,7 @@ static int intersect_rates(const int *source_rates, int source_len,
> > > >  	return k;
> > > >  }
> > > >  
> > > > -static int intel_dp_common_rates(struct intel_dp *intel_dp,
> > > > -				 int *common_rates)
> > > > +int intel_dp_common_rates(struct intel_dp *intel_dp, int *common_rates)
> > > >  {
> > > >  	const int *source_rates, *sink_rates;
> > > >  	int source_len, sink_len;
> > > > @@ -321,7 +320,7 @@ static int intel_dp_common_rates(struct intel_dp *intel_dp,
> > > >  			       common_rates);
> > > >  }
> > > >  
> > > > -static bool intel_dp_upfront_link_train(struct intel_dp *intel_dp)
> > > > +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;
> > > > @@ -4545,12 +4544,12 @@ intel_dp_long_pulse(struct intel_connector *intel_connector)
> > > >  	}
> > > >  
> > > >  out:
> > > > -	if ((status != connector_status_connected) &&
> > > > -	    (intel_dp->is_mst == false)) {
> > > > -		intel_dp_unset_edid(intel_dp);
> > > > +	if (status != connector_status_connected) {
> > > >  		intel_dp->upfront_done = false;
> > > >  		intel_dp->max_lanes_upfront = 0;
> > > >  		intel_dp->max_link_rate_upfront = 0;
> > > > +		if (intel_dp->is_mst == false)
> > > > +			intel_dp_unset_edid(intel_dp);
> > > >  	}
> > > >  
> > > >  	intel_display_power_put(to_i915(dev), power_domain);
> > > > diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c
> > > > index 54a9d76..98d45a4 100644
> > > > --- a/drivers/gpu/drm/i915/intel_dp_mst.c
> > > > +++ b/drivers/gpu/drm/i915/intel_dp_mst.c
> > > > @@ -41,21 +41,30 @@ static bool intel_dp_mst_compute_config(struct intel_encoder *encoder,
> > > >  	int bpp;
> > > >  	int lane_count, slots;
> > > >  	const struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode;
> > > > -	int mst_pbn;
> > > > +	int mst_pbn, common_len;
> > > > +	int common_rates[DP_MAX_SUPPORTED_RATES] = {};
> > > >  
> > > >  	pipe_config->dp_encoder_is_mst = true;
> > > >  	pipe_config->has_pch_encoder = false;
> > > > -	bpp = 24;
> > > > +
> > > >  	/*
> > > > -	 * for MST we always configure max link bw - the spec doesn't
> > > > -	 * seem to suggest we should do otherwise.
> > > > +	 * For MST we always configure for the maximum trainable link bw -
> > > > +	 * the spec doesn't seem to suggest we should do otherwise.  The
> > > > +	 * calls to intel_dp_max_lane_count() and intel_dp_common_rates()
> > > > +	 * both take successful upfront link training into account, and
> > > > +	 * return the DisplayPort max supported values in the event that
> > > > +	 * upfront link training was not done.
> > > >  	 */
> > > > -	lane_count = drm_dp_max_lane_count(intel_dp->dpcd);
> > > > +	lane_count = intel_dp_max_lane_count(intel_dp);
> > > >  
> > > >  	pipe_config->lane_count = lane_count;
> > > >  
> > > > -	pipe_config->pipe_bpp = 24;
> > > > -	pipe_config->port_clock = intel_dp_max_link_rate(intel_dp);
> > > > +	pipe_config->pipe_bpp = bpp = 24;
> > > > +	common_len = intel_dp_common_rates(intel_dp, common_rates);
> > > > +	pipe_config->port_clock = common_rates[common_len - 1];
> > > > +
> > > > +	DRM_DEBUG_KMS("DP MST link configured for %d lanes @ %d.\n",
> > > > +		      pipe_config->lane_count, pipe_config->port_clock);
> > > >  
> > > >  	state = pipe_config->base.state;
> > > >  
> > > > @@ -137,6 +146,8 @@ static void intel_mst_pre_enable_dp(struct intel_encoder *encoder,
> > > >  	enum port port = intel_dig_port->port;
> > > >  	struct intel_connector *connector =
> > > >  		to_intel_connector(conn_state->connector);
> > > > +	struct intel_shared_dpll *pll = pipe_config->shared_dpll;
> > > > +	struct intel_shared_dpll_config tmp_pll_config;
> > > >  	int ret;
> > > >  	uint32_t temp;
> > > >  	int slots;
> > > > @@ -150,21 +161,23 @@ static void intel_mst_pre_enable_dp(struct intel_encoder *encoder,
> > > >  	DRM_DEBUG_KMS("%d\n", intel_dp->active_mst_links);
> > > >  
> > > >  	if (intel_dp->active_mst_links == 0) {
> > > > -		intel_ddi_clk_select(&intel_dig_port->base,
> > > > -				     pipe_config->shared_dpll);
> > > > -
> > > > -		intel_prepare_dp_ddi_buffers(&intel_dig_port->base);
> > > > -		intel_dp_set_link_params(intel_dp,
> > > > -					 pipe_config->port_clock,
> > > > -					 pipe_config->lane_count,
> > > > -					 true);
> > > > -
> > > > -		intel_ddi_init_dp_buf_reg(&intel_dig_port->base);
> > > >  
> > > > -		intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON);
> > > > +		/* Disable the PLL since we need to acquire the PLL
> > > > +		 * based on the link rate in the link training sequence
> > > > +		 */
> > > > +		tmp_pll_config = pll->config;
> > > > +		pll->funcs.disable(dev_priv, pll);
> > > > +		pll->config.crtc_mask = 0;
> > > > +
> > > > +		/* If Link Training fails, send a uevent to generate a
> > > > +		 *hotplug
> > > > +		 */
> > > > +		if (!(intel_ddi_link_train(intel_dp, pipe_config->port_clock,
> > > > +					   pipe_config->lane_count, true,
> > > > +					   false)))
> > > > +			drm_kms_helper_hotplug_event(encoder->base.dev);
> > > > +		pll->config = tmp_pll_config;
> > > >  
> > > > -		intel_dp_start_link_train(intel_dp);
> > > > -		intel_dp_stop_link_train(intel_dp);
> > > >  	}
> > > >  
> > > >  	ret = drm_dp_mst_allocate_vcpi(&intel_dp->mst_mgr,
> > > > @@ -336,6 +349,27 @@ intel_dp_mst_mode_valid(struct drm_connector *connector,
> > > >  			struct drm_display_mode *mode)
> > > >  {
> > > >  	int max_dotclk = to_i915(connector->dev)->max_dotclk_freq;
> > > > +	struct intel_connector *intel_connector = to_intel_connector(connector);
> > > > +	struct intel_dp *intel_dp = intel_connector->mst_port;
> > > > +
> > > > +	if (intel_dp->upfront_link_train && !intel_dp->upfront_done) {
> > > > +		bool do_upfront_link_train;
> > > > +
> > > > +		do_upfront_link_train = 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);
> > > > +			if (intel_dp->upfront_done) {
> > > > +				DRM_DEBUG_KMS("MST upfront trained at "
> > > > +					      "%d lanes @ %d.",
> > > > +					      intel_dp->max_lanes_upfront,
> > > > +					      intel_dp->max_link_rate_upfront);
> > > > +			} else
> > > > +				DRM_DEBUG_KMS("MST upfront link training "
> > > > +					      "failed.");
> > > > +		}
> > > > +	}
> > > >  
> > > >  	/* TODO - validate mode against available PBN for link */
> > > >  	if (mode->clock < 10000)
> > > > diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> > > > index fc2f1bc..b4bc002 100644
> > > > --- a/drivers/gpu/drm/i915/intel_drv.h
> > > > +++ b/drivers/gpu/drm/i915/intel_drv.h
> > > > @@ -1416,6 +1416,7 @@ void intel_edp_panel_off(struct intel_dp *intel_dp);
> > > >  void intel_dp_add_properties(struct intel_dp *intel_dp, struct drm_connector *connector);
> > > >  void intel_dp_mst_suspend(struct drm_device *dev);
> > > >  void intel_dp_mst_resume(struct drm_device *dev);
> > > > +u8 intel_dp_max_lane_count(struct intel_dp *intel_dp);
> > > >  int intel_dp_max_link_rate(struct intel_dp *intel_dp);
> > > >  int intel_dp_link_rate_index(struct intel_dp *intel_dp, int *common_rates,
> > > >  			     int link_rate);
> > > > @@ -1446,6 +1447,8 @@ intel_dp_pre_emphasis_max(struct intel_dp *intel_dp, uint8_t voltage_swing);
> > > >  void intel_dp_compute_rate(struct intel_dp *intel_dp, int port_clock,
> > > >  			   uint8_t *link_bw, uint8_t *rate_select);
> > > >  bool intel_dp_source_supports_hbr2(struct intel_dp *intel_dp);
> > > > +int intel_dp_common_rates(struct intel_dp *intel_dp, int *common_rates);
> > > > +bool intel_dp_upfront_link_train(struct intel_dp *intel_dp);
> > > >  bool
> > > >  intel_dp_get_link_status(struct intel_dp *intel_dp, uint8_t link_status[DP_LINK_STATUS_SIZE]);
> > > >  
> > > 
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx@lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
diff mbox

Patch

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 9042d28..635830e 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -131,7 +131,7 @@  static void vlv_steal_power_sequencer(struct drm_device *dev,
 				      enum pipe pipe);
 static void intel_dp_unset_edid(struct intel_dp *intel_dp);
 
-static int
+int
 intel_dp_max_link_bw(struct intel_dp  *intel_dp)
 {
 	int max_link_bw = intel_dp->dpcd[DP_MAX_LINK_RATE];
@@ -150,7 +150,7 @@  intel_dp_max_link_bw(struct intel_dp  *intel_dp)
 	return max_link_bw;
 }
 
-static u8 intel_dp_max_lane_count(struct intel_dp *intel_dp)
+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 temp, source_max, sink_max;
@@ -296,8 +296,7 @@  static int intersect_rates(const int *source_rates, int source_len,
 	return k;
 }
 
-static int intel_dp_common_rates(struct intel_dp *intel_dp,
-				 int *common_rates)
+int intel_dp_common_rates(struct intel_dp *intel_dp, int *common_rates)
 {
 	const int *source_rates, *sink_rates;
 	int source_len, sink_len;
@@ -321,7 +320,7 @@  static int intel_dp_common_rates(struct intel_dp *intel_dp,
 			       common_rates);
 }
 
-static bool intel_dp_upfront_link_train(struct intel_dp *intel_dp)
+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;
@@ -4545,12 +4544,12 @@  intel_dp_long_pulse(struct intel_connector *intel_connector)
 	}
 
 out:
-	if ((status != connector_status_connected) &&
-	    (intel_dp->is_mst == false)) {
-		intel_dp_unset_edid(intel_dp);
+	if (status != connector_status_connected) {
 		intel_dp->upfront_done = false;
 		intel_dp->max_lanes_upfront = 0;
 		intel_dp->max_link_rate_upfront = 0;
+		if (intel_dp->is_mst == false)
+			intel_dp_unset_edid(intel_dp);
 	}
 
 	intel_display_power_put(to_i915(dev), power_domain);
diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c
index 54a9d76..98d45a4 100644
--- a/drivers/gpu/drm/i915/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/intel_dp_mst.c
@@ -41,21 +41,30 @@  static bool intel_dp_mst_compute_config(struct intel_encoder *encoder,
 	int bpp;
 	int lane_count, slots;
 	const struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode;
-	int mst_pbn;
+	int mst_pbn, common_len;
+	int common_rates[DP_MAX_SUPPORTED_RATES] = {};
 
 	pipe_config->dp_encoder_is_mst = true;
 	pipe_config->has_pch_encoder = false;
-	bpp = 24;
+
 	/*
-	 * for MST we always configure max link bw - the spec doesn't
-	 * seem to suggest we should do otherwise.
+	 * For MST we always configure for the maximum trainable link bw -
+	 * the spec doesn't seem to suggest we should do otherwise.  The
+	 * calls to intel_dp_max_lane_count() and intel_dp_common_rates()
+	 * both take successful upfront link training into account, and
+	 * return the DisplayPort max supported values in the event that
+	 * upfront link training was not done.
 	 */
-	lane_count = drm_dp_max_lane_count(intel_dp->dpcd);
+	lane_count = intel_dp_max_lane_count(intel_dp);
 
 	pipe_config->lane_count = lane_count;
 
-	pipe_config->pipe_bpp = 24;
-	pipe_config->port_clock = intel_dp_max_link_rate(intel_dp);
+	pipe_config->pipe_bpp = bpp = 24;
+	common_len = intel_dp_common_rates(intel_dp, common_rates);
+	pipe_config->port_clock = common_rates[common_len - 1];
+
+	DRM_DEBUG_KMS("DP MST link configured for %d lanes @ %d.\n",
+		      pipe_config->lane_count, pipe_config->port_clock);
 
 	state = pipe_config->base.state;
 
@@ -137,6 +146,8 @@  static void intel_mst_pre_enable_dp(struct intel_encoder *encoder,
 	enum port port = intel_dig_port->port;
 	struct intel_connector *connector =
 		to_intel_connector(conn_state->connector);
+	struct intel_shared_dpll *pll = pipe_config->shared_dpll;
+	struct intel_shared_dpll_config tmp_pll_config;
 	int ret;
 	uint32_t temp;
 	int slots;
@@ -150,21 +161,23 @@  static void intel_mst_pre_enable_dp(struct intel_encoder *encoder,
 	DRM_DEBUG_KMS("%d\n", intel_dp->active_mst_links);
 
 	if (intel_dp->active_mst_links == 0) {
-		intel_ddi_clk_select(&intel_dig_port->base,
-				     pipe_config->shared_dpll);
-
-		intel_prepare_dp_ddi_buffers(&intel_dig_port->base);
-		intel_dp_set_link_params(intel_dp,
-					 pipe_config->port_clock,
-					 pipe_config->lane_count,
-					 true);
-
-		intel_ddi_init_dp_buf_reg(&intel_dig_port->base);
 
-		intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON);
+		/* Disable the PLL since we need to acquire the PLL
+		 * based on the link rate in the link training sequence
+		 */
+		tmp_pll_config = pll->config;
+		pll->funcs.disable(dev_priv, pll);
+		pll->config.crtc_mask = 0;
+
+		/* If Link Training fails, send a uevent to generate a
+		 *hotplug
+		 */
+		if (!(intel_ddi_link_train(intel_dp, pipe_config->port_clock,
+					   pipe_config->lane_count, true,
+					   false)))
+			drm_kms_helper_hotplug_event(encoder->base.dev);
+		pll->config = tmp_pll_config;
 
-		intel_dp_start_link_train(intel_dp);
-		intel_dp_stop_link_train(intel_dp);
 	}
 
 	ret = drm_dp_mst_allocate_vcpi(&intel_dp->mst_mgr,
@@ -336,6 +349,27 @@  intel_dp_mst_mode_valid(struct drm_connector *connector,
 			struct drm_display_mode *mode)
 {
 	int max_dotclk = to_i915(connector->dev)->max_dotclk_freq;
+	struct intel_connector *intel_connector = to_intel_connector(connector);
+	struct intel_dp *intel_dp = intel_connector->mst_port;
+
+	if (intel_dp->upfront_link_train && !intel_dp->upfront_done) {
+		bool do_upfront_link_train;
+
+		do_upfront_link_train = 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);
+			if (intel_dp->upfront_done) {
+				DRM_DEBUG_KMS("MST upfront trained at "
+					      "%d lanes @ %d.",
+					      intel_dp->max_lanes_upfront,
+					      intel_dp->max_link_rate_upfront);
+			} else
+				DRM_DEBUG_KMS("MST upfront link training "
+					      "failed.");
+		}
+	}
 
 	/* TODO - validate mode against available PBN for link */
 	if (mode->clock < 10000)
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index fc2f1bc..b4bc002 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1416,6 +1416,7 @@  void intel_edp_panel_off(struct intel_dp *intel_dp);
 void intel_dp_add_properties(struct intel_dp *intel_dp, struct drm_connector *connector);
 void intel_dp_mst_suspend(struct drm_device *dev);
 void intel_dp_mst_resume(struct drm_device *dev);
+u8 intel_dp_max_lane_count(struct intel_dp *intel_dp);
 int intel_dp_max_link_rate(struct intel_dp *intel_dp);
 int intel_dp_link_rate_index(struct intel_dp *intel_dp, int *common_rates,
 			     int link_rate);
@@ -1446,6 +1447,8 @@  intel_dp_pre_emphasis_max(struct intel_dp *intel_dp, uint8_t voltage_swing);
 void intel_dp_compute_rate(struct intel_dp *intel_dp, int port_clock,
 			   uint8_t *link_bw, uint8_t *rate_select);
 bool intel_dp_source_supports_hbr2(struct intel_dp *intel_dp);
+int intel_dp_common_rates(struct intel_dp *intel_dp, int *common_rates);
+bool intel_dp_upfront_link_train(struct intel_dp *intel_dp);
 bool
 intel_dp_get_link_status(struct intel_dp *intel_dp, uint8_t link_status[DP_LINK_STATUS_SIZE]);