Re: [PATCH v2 3/9] drm/i915/dp: Move vswing/pre-emphasis adjustment calculation

From: "Ville Syrjälä" <ville.syrjala@linux.intel.com>
To: Animesh Manna <animesh.manna@intel.com>
Cc: jani.nikula@intel.com, nidhi1.gupta@intel.com,
	intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
	manasi.d.navare@intel.com, uma.shankar@intel.com,
	anshuman.gupta@intel.com
Subject: Re: [PATCH v2 3/9] drm/i915/dp: Move vswing/pre-emphasis adjustment calculation
Date: Thu, 19 Dec 2019 14:33:10 +0200	[thread overview]
Message-ID: <20191219123310.GG1208@intel.com> (raw)
In-Reply-To: <20191218151350.19579-4-animesh.manna@intel.com>

On Wed, Dec 18, 2019 at 08:43:44PM +0530, Animesh Manna wrote:
> vswing/pre-emphasis adjustment calculation is needed in processing
> of auto phy compliance request other than link training, so moved
> the same function in intel_dp.c.
> 
> No functional change.
> 
> Signed-off-by: Animesh Manna <animesh.manna@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_dp.c       | 32 +++++++++++++++++++
>  drivers/gpu/drm/i915/display/intel_dp.h       |  3 ++
>  .../drm/i915/display/intel_dp_link_training.c | 32 -------------------
>  3 files changed, 35 insertions(+), 32 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index 2f31d226c6eb..ca82835b6dcf 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -4110,6 +4110,38 @@ ivb_cpu_edp_signal_levels(u8 train_set)
>  	}
>  }
>  
> +void
> +intel_get_adjust_train(struct intel_dp *intel_dp,
> +		       const u8 *link_status)

I'd prefer to keep the arrayish notation so we have some idea how big
this is supposed to be. I guess that woukld mean including some
drm dp header in intel_dp.h?

> +{
> +	u8 v = 0;
> +	u8 p = 0;
> +	int lane;
> +	u8 voltage_max;
> +	u8 preemph_max;
> +
> +	for (lane = 0; lane < intel_dp->lane_count; lane++) {
> +		u8 this_v = drm_dp_get_adjust_request_voltage(link_status, lane);
> +		u8 this_p = drm_dp_get_adjust_request_pre_emphasis(link_status, lane);
> +
> +		if (this_v > v)
> +			v = this_v;
> +		if (this_p > p)
> +			p = this_p;
> +	}
> +
> +	voltage_max = intel_dp_voltage_max(intel_dp);
> +	if (v >= voltage_max)
> +		v = voltage_max | DP_TRAIN_MAX_SWING_REACHED;
> +
> +	preemph_max = intel_dp_pre_emphasis_max(intel_dp, v);
> +	if (p >= preemph_max)
> +		p = preemph_max | DP_TRAIN_MAX_PRE_EMPHASIS_REACHED;
> +
> +	for (lane = 0; lane < 4; lane++)
> +		intel_dp->train_set[lane] = v | p;
> +}
> +
>  void
>  intel_dp_set_signal_levels(struct intel_dp *intel_dp)
>  {
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.h b/drivers/gpu/drm/i915/display/intel_dp.h
> index 3da166054788..0d0cb692f701 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.h
> +++ b/drivers/gpu/drm/i915/display/intel_dp.h
> @@ -91,6 +91,9 @@ void
>  intel_dp_program_link_training_pattern(struct intel_dp *intel_dp,
>  				       u8 dp_train_pat);
>  void
> +intel_get_adjust_train(struct intel_dp *intel_dp,
> +		       const u8 *link_status);
> +void
>  intel_dp_set_signal_levels(struct intel_dp *intel_dp);
>  void intel_dp_set_idle_link_train(struct intel_dp *intel_dp);
>  u8
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_link_training.c b/drivers/gpu/drm/i915/display/intel_dp_link_training.c
> index 2a1130dd1ad0..1e38584e7d56 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c
> @@ -34,38 +34,6 @@ intel_dp_dump_link_status(const u8 link_status[DP_LINK_STATUS_SIZE])
>  		      link_status[3], link_status[4], link_status[5]);
>  }
>  
> -static void
> -intel_get_adjust_train(struct intel_dp *intel_dp,
> -		       const u8 link_status[DP_LINK_STATUS_SIZE])
> -{
> -	u8 v = 0;
> -	u8 p = 0;
> -	int lane;
> -	u8 voltage_max;
> -	u8 preemph_max;
> -
> -	for (lane = 0; lane < intel_dp->lane_count; lane++) {
> -		u8 this_v = drm_dp_get_adjust_request_voltage(link_status, lane);
> -		u8 this_p = drm_dp_get_adjust_request_pre_emphasis(link_status, lane);
> -
> -		if (this_v > v)
> -			v = this_v;
> -		if (this_p > p)
> -			p = this_p;
> -	}
> -
> -	voltage_max = intel_dp_voltage_max(intel_dp);
> -	if (v >= voltage_max)
> -		v = voltage_max | DP_TRAIN_MAX_SWING_REACHED;
> -
> -	preemph_max = intel_dp_pre_emphasis_max(intel_dp, v);
> -	if (p >= preemph_max)
> -		p = preemph_max | DP_TRAIN_MAX_PRE_EMPHASIS_REACHED;
> -
> -	for (lane = 0; lane < 4; lane++)
> -		intel_dp->train_set[lane] = v | p;
> -}
> -
>  static bool
>  intel_dp_set_link_train(struct intel_dp *intel_dp,
>  			u8 dp_train_pat)
> -- 
> 2.24.0

-- 
Ville Syrjälä
Intel
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel