[v4,6/7] i915/dp/fec: Configure the Forward Error Correction bits.
diff mbox series

Message ID 20181031004517.17250-7-anusha.srivatsa@intel.com
State New
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Series
  • Forward Error Correction
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Commit Message

Srivatsa, Anusha Oct. 31, 2018, 12:45 a.m. UTC
If FEC is supported, the corresponding
DP_TP_CTL register bits have to be configured.

The driver has to program the FEC_ENABLE in DP_TP_CTL[30] register
and wait till FEC_STATUS in DP_TP_CTL[28] is 1.
Also add the warn message to make sure that the control
register is already active while enabling FEC.

v2:
- Change commit message. Configure fec state after
  link training (Manasi, Gaurav)
- Remove redundent checks (Manasi)
- Remove the registers that get added automagically (Anusha)

v3: s/intel_dp_set_fec_state()/intel_dp_enable_fec_state() (Gaurav)

v4: rebased.

v5:
- Move the code to the proper spot, according to spec.(Ville)
- Use fec state as a check too.

Cc: Gaurav K Singh <gaurav.k.singh@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Cc: Manasi Navare <manasi.d.navare@intel.com>
Signed-off-by: Anusha Srivatsa <anusha.srivatsa@intel.com>
---
 drivers/gpu/drm/i915/i915_reg.h  |  2 ++
 drivers/gpu/drm/i915/intel_ddi.c | 30 ++++++++++++++++++++++++++++++
 drivers/gpu/drm/i915/intel_drv.h |  2 ++
 3 files changed, 34 insertions(+)

Comments

Ville Syrjälä Oct. 31, 2018, 9:08 p.m. UTC | #1
On Tue, Oct 30, 2018 at 05:45:16PM -0700, Anusha Srivatsa wrote:
> If FEC is supported, the corresponding
> DP_TP_CTL register bits have to be configured.
> 
> The driver has to program the FEC_ENABLE in DP_TP_CTL[30] register
> and wait till FEC_STATUS in DP_TP_CTL[28] is 1.
> Also add the warn message to make sure that the control
> register is already active while enabling FEC.
> 
> v2:
> - Change commit message. Configure fec state after
>   link training (Manasi, Gaurav)
> - Remove redundent checks (Manasi)
> - Remove the registers that get added automagically (Anusha)
> 
> v3: s/intel_dp_set_fec_state()/intel_dp_enable_fec_state() (Gaurav)
> 
> v4: rebased.
> 
> v5:
> - Move the code to the proper spot, according to spec.(Ville)
> - Use fec state as a check too.
> 
> Cc: Gaurav K Singh <gaurav.k.singh@intel.com>
> Cc: Jani Nikula <jani.nikula@linux.intel.com>
> Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
> Cc: Manasi Navare <manasi.d.navare@intel.com>
> Signed-off-by: Anusha Srivatsa <anusha.srivatsa@intel.com>
> ---
>  drivers/gpu/drm/i915/i915_reg.h  |  2 ++
>  drivers/gpu/drm/i915/intel_ddi.c | 30 ++++++++++++++++++++++++++++++
>  drivers/gpu/drm/i915/intel_drv.h |  2 ++
>  3 files changed, 34 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index e85f53cb9cdd..8b1753939299 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -9134,6 +9134,7 @@ enum skl_power_gate {
>  #define _DP_TP_CTL_B			0x64140
>  #define DP_TP_CTL(port) _MMIO_PORT(port, _DP_TP_CTL_A, _DP_TP_CTL_B)
>  #define  DP_TP_CTL_ENABLE			(1 << 31)
> +#define  DP_TP_CTL_FEC_ENABLE			(1 << 30)
>  #define  DP_TP_CTL_MODE_SST			(0 << 27)
>  #define  DP_TP_CTL_MODE_MST			(1 << 27)
>  #define  DP_TP_CTL_FORCE_ACT			(1 << 25)
> @@ -9152,6 +9153,7 @@ enum skl_power_gate {
>  #define _DP_TP_STATUS_A			0x64044
>  #define _DP_TP_STATUS_B			0x64144
>  #define DP_TP_STATUS(port) _MMIO_PORT(port, _DP_TP_STATUS_A, _DP_TP_STATUS_B)
> +#define  DP_TP_STATUS_FEC_ENABLE_LIVE		(1 << 28)
>  #define  DP_TP_STATUS_IDLE_DONE			(1 << 25)
>  #define  DP_TP_STATUS_ACT_SENT			(1 << 24)
>  #define  DP_TP_STATUS_MODE_STATUS_MST		(1 << 23)
> diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
> index efbada95dc4e..f03f44f332c7 100644
> --- a/drivers/gpu/drm/i915/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/intel_ddi.c
> @@ -2889,6 +2889,32 @@ static void intel_ddi_clk_disable(struct intel_encoder *encoder)
>  	}
>  }
>  
> +void intel_dp_enable_fec_state(struct intel_dp *intel_dp,
> +			       const struct intel_crtc_state *crtc_state)

Can be static. intel_ddi_enable_fec() seems like a better name,
and we can just pass the intel_encoder to this I think. No need to 
do all the "intel_dp to encoder" gynmastics then.

> +{
> +	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
> +	struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
> +	enum port port = intel_dig_port->base.port;
> +	u32 val;
> +
> +	/* FEC support exists for DP 1.4 only */

This comment is misleading. There are other reasons besides < DP 1.4 for
not using FEC. IMO just drop the comment.

> +	if (!crtc_state->fec_enable)
> +		return;
> +
> +	if (!crtc_state->dsc_params.compression_enable)
> +		return;

That check can be removed now.

> +
> +	val = I915_READ(DP_TP_CTL(port));
> +	val |= DP_TP_CTL_FEC_ENABLE;
> +	I915_WRITE(DP_TP_CTL(port), val);
> +
> +	if (intel_wait_for_register(dev_priv, DP_TP_STATUS(port),
> +				    DP_TP_STATUS_FEC_ENABLE_LIVE,
> +				    DP_TP_STATUS_FEC_ENABLE_LIVE,
> +				    1))
> +		DRM_ERROR("Timed out waiting for FEC Enable Status\n");
> +}
> +
>  static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder,
>  				    const struct intel_crtc_state *crtc_state,
>  				    const struct drm_connector_state *conn_state)
> @@ -2934,9 +2960,13 @@ static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder,
>  					      DP_DECOMPRESSION_EN);
>  	intel_dp_sink_set_fec_ready(intel_dp, crtc_state, DP_FEC_READY);
>  	intel_dp_start_link_train(intel_dp);
> +

Unrelated whitespace change.

>  	if (port != PORT_A || INTEL_GEN(dev_priv) >= 9)
>  		intel_dp_stop_link_train(intel_dp);
>  
> +	/* Set FEC state after link training */

Redundant comment.

> +	intel_dp_enable_fec_state(intel_dp, crtc_state);
> +
>  	icl_enable_phy_clock_gating(dig_port);
>  
>  	if (!is_mst)
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index 2a080205968d..1cdfa9c5da43 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -1799,6 +1799,8 @@ void intel_dp_sink_set_decompression_state(struct intel_dp *intel_dp,
>  void intel_dp_sink_set_fec_ready(struct intel_dp *intel_dp,
>  				 const struct intel_crtc_state *crtc_state,
>  				 int state);
> +void intel_dp_enable_fec_state(struct intel_dp *intel_dp,
> +			       const struct intel_crtc_state *crtc_state);
>  void intel_dp_encoder_reset(struct drm_encoder *encoder);
>  void intel_dp_encoder_suspend(struct intel_encoder *intel_encoder);
>  void intel_dp_encoder_destroy(struct drm_encoder *encoder);
> -- 
> 2.17.1
Srivatsa, Anusha Oct. 31, 2018, 10:34 p.m. UTC | #2
>-----Original Message-----
>From: Ville Syrjälä [mailto:ville.syrjala@linux.intel.com]
>Sent: Wednesday, October 31, 2018 2:08 PM
>To: Srivatsa, Anusha <anusha.srivatsa@intel.com>
>Cc: intel-gfx@lists.freedesktop.org; Singh, Gaurav K <gaurav.k.singh@intel.com>;
>Jani Nikula <jani.nikula@linux.intel.com>; Navare, Manasi D
><manasi.d.navare@intel.com>
>Subject: Re: [v4 6/7] i915/dp/fec: Configure the Forward Error Correction bits.
>
>On Tue, Oct 30, 2018 at 05:45:16PM -0700, Anusha Srivatsa wrote:
>> If FEC is supported, the corresponding DP_TP_CTL register bits have to
>> be configured.
>>
>> The driver has to program the FEC_ENABLE in DP_TP_CTL[30] register and
>> wait till FEC_STATUS in DP_TP_CTL[28] is 1.
>> Also add the warn message to make sure that the control register is
>> already active while enabling FEC.
>>
>> v2:
>> - Change commit message. Configure fec state after
>>   link training (Manasi, Gaurav)
>> - Remove redundent checks (Manasi)
>> - Remove the registers that get added automagically (Anusha)
>>
>> v3: s/intel_dp_set_fec_state()/intel_dp_enable_fec_state() (Gaurav)
>>
>> v4: rebased.
>>
>> v5:
>> - Move the code to the proper spot, according to spec.(Ville)
>> - Use fec state as a check too.
>>
>> Cc: Gaurav K Singh <gaurav.k.singh@intel.com>
>> Cc: Jani Nikula <jani.nikula@linux.intel.com>
>> Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
>> Cc: Manasi Navare <manasi.d.navare@intel.com>
>> Signed-off-by: Anusha Srivatsa <anusha.srivatsa@intel.com>
>> ---
>>  drivers/gpu/drm/i915/i915_reg.h  |  2 ++
>> drivers/gpu/drm/i915/intel_ddi.c | 30 ++++++++++++++++++++++++++++++
>> drivers/gpu/drm/i915/intel_drv.h |  2 ++
>>  3 files changed, 34 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_reg.h
>> b/drivers/gpu/drm/i915/i915_reg.h index e85f53cb9cdd..8b1753939299
>> 100644
>> --- a/drivers/gpu/drm/i915/i915_reg.h
>> +++ b/drivers/gpu/drm/i915/i915_reg.h
>> @@ -9134,6 +9134,7 @@ enum skl_power_gate {
>>  #define _DP_TP_CTL_B			0x64140
>>  #define DP_TP_CTL(port) _MMIO_PORT(port, _DP_TP_CTL_A, _DP_TP_CTL_B)
>>  #define  DP_TP_CTL_ENABLE			(1 << 31)
>> +#define  DP_TP_CTL_FEC_ENABLE			(1 << 30)
>>  #define  DP_TP_CTL_MODE_SST			(0 << 27)
>>  #define  DP_TP_CTL_MODE_MST			(1 << 27)
>>  #define  DP_TP_CTL_FORCE_ACT			(1 << 25)
>> @@ -9152,6 +9153,7 @@ enum skl_power_gate {
>>  #define _DP_TP_STATUS_A			0x64044
>>  #define _DP_TP_STATUS_B			0x64144
>>  #define DP_TP_STATUS(port) _MMIO_PORT(port, _DP_TP_STATUS_A,
>> _DP_TP_STATUS_B)
>> +#define  DP_TP_STATUS_FEC_ENABLE_LIVE		(1 << 28)
>>  #define  DP_TP_STATUS_IDLE_DONE			(1 << 25)
>>  #define  DP_TP_STATUS_ACT_SENT			(1 << 24)
>>  #define  DP_TP_STATUS_MODE_STATUS_MST		(1 << 23)
>> diff --git a/drivers/gpu/drm/i915/intel_ddi.c
>> b/drivers/gpu/drm/i915/intel_ddi.c
>> index efbada95dc4e..f03f44f332c7 100644
>> --- a/drivers/gpu/drm/i915/intel_ddi.c
>> +++ b/drivers/gpu/drm/i915/intel_ddi.c
>> @@ -2889,6 +2889,32 @@ static void intel_ddi_clk_disable(struct
>intel_encoder *encoder)
>>  	}
>>  }
>>
>> +void intel_dp_enable_fec_state(struct intel_dp *intel_dp,
>> +			       const struct intel_crtc_state *crtc_state)
>
>Can be static. intel_ddi_enable_fec() seems like a better name, and we can just
>pass the intel_encoder to this I think. No need to do all the "intel_dp to encoder"
>gynmastics then.
intel_ddi_enable_fec() is a better name. 

>> +{
>> +	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
>> +	struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
>> +	enum port port = intel_dig_port->base.port;
>> +	u32 val;
>> +
>> +	/* FEC support exists for DP 1.4 only */
>
>This comment is misleading. There are other reasons besides < DP 1.4 for not
>using FEC. IMO just drop the comment.

Ok.

>> +	if (!crtc_state->fec_enable)
>> +		return;
>> +
>> +	if (!crtc_state->dsc_params.compression_enable)
>> +		return;
>
>That check can be removed now.
No we will still need this. The fec_enable state is not coupled with compression. So we have to check fec state and the compression ....

Anusha 
>> +
>> +	val = I915_READ(DP_TP_CTL(port));
>> +	val |= DP_TP_CTL_FEC_ENABLE;
>> +	I915_WRITE(DP_TP_CTL(port), val);
>> +
>> +	if (intel_wait_for_register(dev_priv, DP_TP_STATUS(port),
>> +				    DP_TP_STATUS_FEC_ENABLE_LIVE,
>> +				    DP_TP_STATUS_FEC_ENABLE_LIVE,
>> +				    1))
>> +		DRM_ERROR("Timed out waiting for FEC Enable Status\n"); }
>> +
>>  static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder,
>>  				    const struct intel_crtc_state *crtc_state,
>>  				    const struct drm_connector_state
>*conn_state) @@ -2934,9
>> +2960,13 @@ static void intel_ddi_pre_enable_dp(struct intel_encoder
>*encoder,
>>  					      DP_DECOMPRESSION_EN);
>>  	intel_dp_sink_set_fec_ready(intel_dp, crtc_state, DP_FEC_READY);
>>  	intel_dp_start_link_train(intel_dp);
>> +
>
>Unrelated whitespace change.
>
>>  	if (port != PORT_A || INTEL_GEN(dev_priv) >= 9)
>>  		intel_dp_stop_link_train(intel_dp);
>>
>> +	/* Set FEC state after link training */
>
>Redundant comment.
>
>> +	intel_dp_enable_fec_state(intel_dp, crtc_state);
>> +
>>  	icl_enable_phy_clock_gating(dig_port);
>>
>>  	if (!is_mst)
>> diff --git a/drivers/gpu/drm/i915/intel_drv.h
>> b/drivers/gpu/drm/i915/intel_drv.h
>> index 2a080205968d..1cdfa9c5da43 100644
>> --- a/drivers/gpu/drm/i915/intel_drv.h
>> +++ b/drivers/gpu/drm/i915/intel_drv.h
>> @@ -1799,6 +1799,8 @@ void
>> intel_dp_sink_set_decompression_state(struct intel_dp *intel_dp,  void
>intel_dp_sink_set_fec_ready(struct intel_dp *intel_dp,
>>  				 const struct intel_crtc_state *crtc_state,
>>  				 int state);
>> +void intel_dp_enable_fec_state(struct intel_dp *intel_dp,
>> +			       const struct intel_crtc_state *crtc_state);
>>  void intel_dp_encoder_reset(struct drm_encoder *encoder);  void
>> intel_dp_encoder_suspend(struct intel_encoder *intel_encoder);  void
>> intel_dp_encoder_destroy(struct drm_encoder *encoder);
>> --
>> 2.17.1
>
>--
>Ville Syrjälä
>Intel
Ville Syrjälä Nov. 2, 2018, 11:16 a.m. UTC | #3
On Wed, Oct 31, 2018 at 10:34:31PM +0000, Srivatsa, Anusha wrote:
> 
> 
> >-----Original Message-----
> >From: Ville Syrjälä [mailto:ville.syrjala@linux.intel.com]
> >Sent: Wednesday, October 31, 2018 2:08 PM
> >To: Srivatsa, Anusha <anusha.srivatsa@intel.com>
> >Cc: intel-gfx@lists.freedesktop.org; Singh, Gaurav K <gaurav.k.singh@intel.com>;
> >Jani Nikula <jani.nikula@linux.intel.com>; Navare, Manasi D
> ><manasi.d.navare@intel.com>
> >Subject: Re: [v4 6/7] i915/dp/fec: Configure the Forward Error Correction bits.
> >
> >On Tue, Oct 30, 2018 at 05:45:16PM -0700, Anusha Srivatsa wrote:
> >> If FEC is supported, the corresponding DP_TP_CTL register bits have to
> >> be configured.
> >>
> >> The driver has to program the FEC_ENABLE in DP_TP_CTL[30] register and
> >> wait till FEC_STATUS in DP_TP_CTL[28] is 1.
> >> Also add the warn message to make sure that the control register is
> >> already active while enabling FEC.
> >>
> >> v2:
> >> - Change commit message. Configure fec state after
> >>   link training (Manasi, Gaurav)
> >> - Remove redundent checks (Manasi)
> >> - Remove the registers that get added automagically (Anusha)
> >>
> >> v3: s/intel_dp_set_fec_state()/intel_dp_enable_fec_state() (Gaurav)
> >>
> >> v4: rebased.
> >>
> >> v5:
> >> - Move the code to the proper spot, according to spec.(Ville)
> >> - Use fec state as a check too.
> >>
> >> Cc: Gaurav K Singh <gaurav.k.singh@intel.com>
> >> Cc: Jani Nikula <jani.nikula@linux.intel.com>
> >> Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
> >> Cc: Manasi Navare <manasi.d.navare@intel.com>
> >> Signed-off-by: Anusha Srivatsa <anusha.srivatsa@intel.com>
> >> ---
> >>  drivers/gpu/drm/i915/i915_reg.h  |  2 ++
> >> drivers/gpu/drm/i915/intel_ddi.c | 30 ++++++++++++++++++++++++++++++
> >> drivers/gpu/drm/i915/intel_drv.h |  2 ++
> >>  3 files changed, 34 insertions(+)
> >>
> >> diff --git a/drivers/gpu/drm/i915/i915_reg.h
> >> b/drivers/gpu/drm/i915/i915_reg.h index e85f53cb9cdd..8b1753939299
> >> 100644
> >> --- a/drivers/gpu/drm/i915/i915_reg.h
> >> +++ b/drivers/gpu/drm/i915/i915_reg.h
> >> @@ -9134,6 +9134,7 @@ enum skl_power_gate {
> >>  #define _DP_TP_CTL_B			0x64140
> >>  #define DP_TP_CTL(port) _MMIO_PORT(port, _DP_TP_CTL_A, _DP_TP_CTL_B)
> >>  #define  DP_TP_CTL_ENABLE			(1 << 31)
> >> +#define  DP_TP_CTL_FEC_ENABLE			(1 << 30)
> >>  #define  DP_TP_CTL_MODE_SST			(0 << 27)
> >>  #define  DP_TP_CTL_MODE_MST			(1 << 27)
> >>  #define  DP_TP_CTL_FORCE_ACT			(1 << 25)
> >> @@ -9152,6 +9153,7 @@ enum skl_power_gate {
> >>  #define _DP_TP_STATUS_A			0x64044
> >>  #define _DP_TP_STATUS_B			0x64144
> >>  #define DP_TP_STATUS(port) _MMIO_PORT(port, _DP_TP_STATUS_A,
> >> _DP_TP_STATUS_B)
> >> +#define  DP_TP_STATUS_FEC_ENABLE_LIVE		(1 << 28)
> >>  #define  DP_TP_STATUS_IDLE_DONE			(1 << 25)
> >>  #define  DP_TP_STATUS_ACT_SENT			(1 << 24)
> >>  #define  DP_TP_STATUS_MODE_STATUS_MST		(1 << 23)
> >> diff --git a/drivers/gpu/drm/i915/intel_ddi.c
> >> b/drivers/gpu/drm/i915/intel_ddi.c
> >> index efbada95dc4e..f03f44f332c7 100644
> >> --- a/drivers/gpu/drm/i915/intel_ddi.c
> >> +++ b/drivers/gpu/drm/i915/intel_ddi.c
> >> @@ -2889,6 +2889,32 @@ static void intel_ddi_clk_disable(struct
> >intel_encoder *encoder)
> >>  	}
> >>  }
> >>
> >> +void intel_dp_enable_fec_state(struct intel_dp *intel_dp,
> >> +			       const struct intel_crtc_state *crtc_state)
> >
> >Can be static. intel_ddi_enable_fec() seems like a better name, and we can just
> >pass the intel_encoder to this I think. No need to do all the "intel_dp to encoder"
> >gynmastics then.
> intel_ddi_enable_fec() is a better name. 
> 
> >> +{
> >> +	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
> >> +	struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
> >> +	enum port port = intel_dig_port->base.port;
> >> +	u32 val;
> >> +
> >> +	/* FEC support exists for DP 1.4 only */
> >
> >This comment is misleading. There are other reasons besides < DP 1.4 for not
> >using FEC. IMO just drop the comment.
> 
> Ok.
> 
> >> +	if (!crtc_state->fec_enable)
> >> +		return;
> >> +
> >> +	if (!crtc_state->dsc_params.compression_enable)
> >> +		return;
> >
> >That check can be removed now.
> No we will still need this. The fec_enable state is not coupled with compression. So we have to check fec state and the compression ....
> 

Either we enable/disable fec or not. Whatever linkage with DSC only
exists in compute_config().

> Anusha 
> >> +
> >> +	val = I915_READ(DP_TP_CTL(port));
> >> +	val |= DP_TP_CTL_FEC_ENABLE;
> >> +	I915_WRITE(DP_TP_CTL(port), val);
> >> +
> >> +	if (intel_wait_for_register(dev_priv, DP_TP_STATUS(port),
> >> +				    DP_TP_STATUS_FEC_ENABLE_LIVE,
> >> +				    DP_TP_STATUS_FEC_ENABLE_LIVE,
> >> +				    1))
> >> +		DRM_ERROR("Timed out waiting for FEC Enable Status\n"); }
> >> +
> >>  static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder,
> >>  				    const struct intel_crtc_state *crtc_state,
> >>  				    const struct drm_connector_state
> >*conn_state) @@ -2934,9
> >> +2960,13 @@ static void intel_ddi_pre_enable_dp(struct intel_encoder
> >*encoder,
> >>  					      DP_DECOMPRESSION_EN);
> >>  	intel_dp_sink_set_fec_ready(intel_dp, crtc_state, DP_FEC_READY);
> >>  	intel_dp_start_link_train(intel_dp);
> >> +
> >
> >Unrelated whitespace change.
> >
> >>  	if (port != PORT_A || INTEL_GEN(dev_priv) >= 9)
> >>  		intel_dp_stop_link_train(intel_dp);
> >>
> >> +	/* Set FEC state after link training */
> >
> >Redundant comment.
> >
> >> +	intel_dp_enable_fec_state(intel_dp, crtc_state);
> >> +
> >>  	icl_enable_phy_clock_gating(dig_port);
> >>
> >>  	if (!is_mst)
> >> diff --git a/drivers/gpu/drm/i915/intel_drv.h
> >> b/drivers/gpu/drm/i915/intel_drv.h
> >> index 2a080205968d..1cdfa9c5da43 100644
> >> --- a/drivers/gpu/drm/i915/intel_drv.h
> >> +++ b/drivers/gpu/drm/i915/intel_drv.h
> >> @@ -1799,6 +1799,8 @@ void
> >> intel_dp_sink_set_decompression_state(struct intel_dp *intel_dp,  void
> >intel_dp_sink_set_fec_ready(struct intel_dp *intel_dp,
> >>  				 const struct intel_crtc_state *crtc_state,
> >>  				 int state);
> >> +void intel_dp_enable_fec_state(struct intel_dp *intel_dp,
> >> +			       const struct intel_crtc_state *crtc_state);
> >>  void intel_dp_encoder_reset(struct drm_encoder *encoder);  void
> >> intel_dp_encoder_suspend(struct intel_encoder *intel_encoder);  void
> >> intel_dp_encoder_destroy(struct drm_encoder *encoder);
> >> --
> >> 2.17.1
> >
> >--
> >Ville Syrjälä
> >Intel
Srivatsa, Anusha Nov. 2, 2018, 5:54 p.m. UTC | #4
>-----Original Message-----
>From: Ville Syrjälä [mailto:ville.syrjala@linux.intel.com]
>Sent: Friday, November 2, 2018 4:16 AM
>To: Srivatsa, Anusha <anusha.srivatsa@intel.com>
>Cc: intel-gfx@lists.freedesktop.org; Singh, Gaurav K <gaurav.k.singh@intel.com>;
>Jani Nikula <jani.nikula@linux.intel.com>; Navare, Manasi D
><manasi.d.navare@intel.com>
>Subject: Re: [v4 6/7] i915/dp/fec: Configure the Forward Error Correction bits.
>
>On Wed, Oct 31, 2018 at 10:34:31PM +0000, Srivatsa, Anusha wrote:
>>
>>
>> >-----Original Message-----
>> >From: Ville Syrjälä [mailto:ville.syrjala@linux.intel.com]
>> >Sent: Wednesday, October 31, 2018 2:08 PM
>> >To: Srivatsa, Anusha <anusha.srivatsa@intel.com>
>> >Cc: intel-gfx@lists.freedesktop.org; Singh, Gaurav K
>> ><gaurav.k.singh@intel.com>; Jani Nikula
>> ><jani.nikula@linux.intel.com>; Navare, Manasi D
>> ><manasi.d.navare@intel.com>
>> >Subject: Re: [v4 6/7] i915/dp/fec: Configure the Forward Error Correction bits.
>> >
>> >On Tue, Oct 30, 2018 at 05:45:16PM -0700, Anusha Srivatsa wrote:
>> >> If FEC is supported, the corresponding DP_TP_CTL register bits have
>> >> to be configured.
>> >>
>> >> The driver has to program the FEC_ENABLE in DP_TP_CTL[30] register
>> >> and wait till FEC_STATUS in DP_TP_CTL[28] is 1.
>> >> Also add the warn message to make sure that the control register is
>> >> already active while enabling FEC.
>> >>
>> >> v2:
>> >> - Change commit message. Configure fec state after
>> >>   link training (Manasi, Gaurav)
>> >> - Remove redundent checks (Manasi)
>> >> - Remove the registers that get added automagically (Anusha)
>> >>
>> >> v3: s/intel_dp_set_fec_state()/intel_dp_enable_fec_state() (Gaurav)
>> >>
>> >> v4: rebased.
>> >>
>> >> v5:
>> >> - Move the code to the proper spot, according to spec.(Ville)
>> >> - Use fec state as a check too.
>> >>
>> >> Cc: Gaurav K Singh <gaurav.k.singh@intel.com>
>> >> Cc: Jani Nikula <jani.nikula@linux.intel.com>
>> >> Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
>> >> Cc: Manasi Navare <manasi.d.navare@intel.com>
>> >> Signed-off-by: Anusha Srivatsa <anusha.srivatsa@intel.com>
>> >> ---
>> >>  drivers/gpu/drm/i915/i915_reg.h  |  2 ++
>> >> drivers/gpu/drm/i915/intel_ddi.c | 30
>> >> ++++++++++++++++++++++++++++++ drivers/gpu/drm/i915/intel_drv.h |
>> >> 2 ++
>> >>  3 files changed, 34 insertions(+)
>> >>
>> >> diff --git a/drivers/gpu/drm/i915/i915_reg.h
>> >> b/drivers/gpu/drm/i915/i915_reg.h index e85f53cb9cdd..8b1753939299
>> >> 100644
>> >> --- a/drivers/gpu/drm/i915/i915_reg.h
>> >> +++ b/drivers/gpu/drm/i915/i915_reg.h
>> >> @@ -9134,6 +9134,7 @@ enum skl_power_gate {
>> >>  #define _DP_TP_CTL_B			0x64140
>> >>  #define DP_TP_CTL(port) _MMIO_PORT(port, _DP_TP_CTL_A,
>_DP_TP_CTL_B)
>> >>  #define  DP_TP_CTL_ENABLE			(1 << 31)
>> >> +#define  DP_TP_CTL_FEC_ENABLE			(1 << 30)
>> >>  #define  DP_TP_CTL_MODE_SST			(0 << 27)
>> >>  #define  DP_TP_CTL_MODE_MST			(1 << 27)
>> >>  #define  DP_TP_CTL_FORCE_ACT			(1 << 25)
>> >> @@ -9152,6 +9153,7 @@ enum skl_power_gate {
>> >>  #define _DP_TP_STATUS_A			0x64044
>> >>  #define _DP_TP_STATUS_B			0x64144
>> >>  #define DP_TP_STATUS(port) _MMIO_PORT(port, _DP_TP_STATUS_A,
>> >> _DP_TP_STATUS_B)
>> >> +#define  DP_TP_STATUS_FEC_ENABLE_LIVE		(1 << 28)
>> >>  #define  DP_TP_STATUS_IDLE_DONE			(1 << 25)
>> >>  #define  DP_TP_STATUS_ACT_SENT			(1 << 24)
>> >>  #define  DP_TP_STATUS_MODE_STATUS_MST		(1 << 23)
>> >> diff --git a/drivers/gpu/drm/i915/intel_ddi.c
>> >> b/drivers/gpu/drm/i915/intel_ddi.c
>> >> index efbada95dc4e..f03f44f332c7 100644
>> >> --- a/drivers/gpu/drm/i915/intel_ddi.c
>> >> +++ b/drivers/gpu/drm/i915/intel_ddi.c
>> >> @@ -2889,6 +2889,32 @@ static void intel_ddi_clk_disable(struct
>> >intel_encoder *encoder)
>> >>  	}
>> >>  }
>> >>
>> >> +void intel_dp_enable_fec_state(struct intel_dp *intel_dp,
>> >> +			       const struct intel_crtc_state *crtc_state)
>> >
>> >Can be static. intel_ddi_enable_fec() seems like a better name, and
>> >we can just pass the intel_encoder to this I think. No need to do all the
>"intel_dp to encoder"
>> >gynmastics then.
>> intel_ddi_enable_fec() is a better name.
>>
>> >> +{
>> >> +	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
>> >> +	struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
>> >> +	enum port port = intel_dig_port->base.port;
>> >> +	u32 val;
>> >> +
>> >> +	/* FEC support exists for DP 1.4 only */
>> >
>> >This comment is misleading. There are other reasons besides < DP 1.4
>> >for not using FEC. IMO just drop the comment.
>>
>> Ok.
>>
>> >> +	if (!crtc_state->fec_enable)
>> >> +		return;
>> >> +
>> >> +	if (!crtc_state->dsc_params.compression_enable)
>> >> +		return;
>> >
>> >That check can be removed now.
>> No we will still need this. The fec_enable state is not coupled with compression.
>So we have to check fec state and the compression ....
>>
>
>Either we enable/disable fec or not. Whatever linkage with DSC only exists in
>compute_config().

True, I have changed this in v5.

Anusha
>> Anusha
>> >> +
>> >> +	val = I915_READ(DP_TP_CTL(port));
>> >> +	val |= DP_TP_CTL_FEC_ENABLE;
>> >> +	I915_WRITE(DP_TP_CTL(port), val);
>> >> +
>> >> +	if (intel_wait_for_register(dev_priv, DP_TP_STATUS(port),
>> >> +				    DP_TP_STATUS_FEC_ENABLE_LIVE,
>> >> +				    DP_TP_STATUS_FEC_ENABLE_LIVE,
>> >> +				    1))
>> >> +		DRM_ERROR("Timed out waiting for FEC Enable Status\n"); }
>> >> +
>> >>  static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder,
>> >>  				    const struct intel_crtc_state *crtc_state,
>> >>  				    const struct drm_connector_state
>> >*conn_state) @@ -2934,9
>> >> +2960,13 @@ static void intel_ddi_pre_enable_dp(struct
>> >> +intel_encoder
>> >*encoder,
>> >>  					      DP_DECOMPRESSION_EN);
>> >>  	intel_dp_sink_set_fec_ready(intel_dp, crtc_state, DP_FEC_READY);
>> >>  	intel_dp_start_link_train(intel_dp);
>> >> +
>> >
>> >Unrelated whitespace change.
>> >
>> >>  	if (port != PORT_A || INTEL_GEN(dev_priv) >= 9)
>> >>  		intel_dp_stop_link_train(intel_dp);
>> >>
>> >> +	/* Set FEC state after link training */
>> >
>> >Redundant comment.
>> >
>> >> +	intel_dp_enable_fec_state(intel_dp, crtc_state);
>> >> +
>> >>  	icl_enable_phy_clock_gating(dig_port);
>> >>
>> >>  	if (!is_mst)
>> >> diff --git a/drivers/gpu/drm/i915/intel_drv.h
>> >> b/drivers/gpu/drm/i915/intel_drv.h
>> >> index 2a080205968d..1cdfa9c5da43 100644
>> >> --- a/drivers/gpu/drm/i915/intel_drv.h
>> >> +++ b/drivers/gpu/drm/i915/intel_drv.h
>> >> @@ -1799,6 +1799,8 @@ void
>> >> intel_dp_sink_set_decompression_state(struct intel_dp *intel_dp,
>> >> void
>> >intel_dp_sink_set_fec_ready(struct intel_dp *intel_dp,
>> >>  				 const struct intel_crtc_state *crtc_state,
>> >>  				 int state);
>> >> +void intel_dp_enable_fec_state(struct intel_dp *intel_dp,
>> >> +			       const struct intel_crtc_state *crtc_state);
>> >>  void intel_dp_encoder_reset(struct drm_encoder *encoder);  void
>> >> intel_dp_encoder_suspend(struct intel_encoder *intel_encoder);
>> >> void intel_dp_encoder_destroy(struct drm_encoder *encoder);
>> >> --
>> >> 2.17.1
>> >
>> >--
>> >Ville Syrjälä
>> >Intel
>
>--
>Ville Syrjälä
>Intel

Patch
diff mbox series

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index e85f53cb9cdd..8b1753939299 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -9134,6 +9134,7 @@  enum skl_power_gate {
 #define _DP_TP_CTL_B			0x64140
 #define DP_TP_CTL(port) _MMIO_PORT(port, _DP_TP_CTL_A, _DP_TP_CTL_B)
 #define  DP_TP_CTL_ENABLE			(1 << 31)
+#define  DP_TP_CTL_FEC_ENABLE			(1 << 30)
 #define  DP_TP_CTL_MODE_SST			(0 << 27)
 #define  DP_TP_CTL_MODE_MST			(1 << 27)
 #define  DP_TP_CTL_FORCE_ACT			(1 << 25)
@@ -9152,6 +9153,7 @@  enum skl_power_gate {
 #define _DP_TP_STATUS_A			0x64044
 #define _DP_TP_STATUS_B			0x64144
 #define DP_TP_STATUS(port) _MMIO_PORT(port, _DP_TP_STATUS_A, _DP_TP_STATUS_B)
+#define  DP_TP_STATUS_FEC_ENABLE_LIVE		(1 << 28)
 #define  DP_TP_STATUS_IDLE_DONE			(1 << 25)
 #define  DP_TP_STATUS_ACT_SENT			(1 << 24)
 #define  DP_TP_STATUS_MODE_STATUS_MST		(1 << 23)
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index efbada95dc4e..f03f44f332c7 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -2889,6 +2889,32 @@  static void intel_ddi_clk_disable(struct intel_encoder *encoder)
 	}
 }
 
+void intel_dp_enable_fec_state(struct intel_dp *intel_dp,
+			       const struct intel_crtc_state *crtc_state)
+{
+	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
+	struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
+	enum port port = intel_dig_port->base.port;
+	u32 val;
+
+	/* FEC support exists for DP 1.4 only */
+	if (!crtc_state->fec_enable)
+		return;
+
+	if (!crtc_state->dsc_params.compression_enable)
+		return;
+
+	val = I915_READ(DP_TP_CTL(port));
+	val |= DP_TP_CTL_FEC_ENABLE;
+	I915_WRITE(DP_TP_CTL(port), val);
+
+	if (intel_wait_for_register(dev_priv, DP_TP_STATUS(port),
+				    DP_TP_STATUS_FEC_ENABLE_LIVE,
+				    DP_TP_STATUS_FEC_ENABLE_LIVE,
+				    1))
+		DRM_ERROR("Timed out waiting for FEC Enable Status\n");
+}
+
 static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder,
 				    const struct intel_crtc_state *crtc_state,
 				    const struct drm_connector_state *conn_state)
@@ -2934,9 +2960,13 @@  static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder,
 					      DP_DECOMPRESSION_EN);
 	intel_dp_sink_set_fec_ready(intel_dp, crtc_state, DP_FEC_READY);
 	intel_dp_start_link_train(intel_dp);
+
 	if (port != PORT_A || INTEL_GEN(dev_priv) >= 9)
 		intel_dp_stop_link_train(intel_dp);
 
+	/* Set FEC state after link training */
+	intel_dp_enable_fec_state(intel_dp, crtc_state);
+
 	icl_enable_phy_clock_gating(dig_port);
 
 	if (!is_mst)
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 2a080205968d..1cdfa9c5da43 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1799,6 +1799,8 @@  void intel_dp_sink_set_decompression_state(struct intel_dp *intel_dp,
 void intel_dp_sink_set_fec_ready(struct intel_dp *intel_dp,
 				 const struct intel_crtc_state *crtc_state,
 				 int state);
+void intel_dp_enable_fec_state(struct intel_dp *intel_dp,
+			       const struct intel_crtc_state *crtc_state);
 void intel_dp_encoder_reset(struct drm_encoder *encoder);
 void intel_dp_encoder_suspend(struct intel_encoder *intel_encoder);
 void intel_dp_encoder_destroy(struct drm_encoder *encoder);