[PATCH 08/14] drm/i915/dp: Add helpers to set link training mode, BW parameters

[Kandpal, Suraj]

> -----Original Message-----
> From: Intel-gfx <intel-gfx-bounces at lists.freedesktop.org> On Behalf Of Imre
> Deak
> Sent: Monday, July 22, 2024 10:25 PM
> To: intel-gfx at lists.freedesktop.org
> Subject: [PATCH 08/14] drm/i915/dp: Add helpers to set link training mode, BW
> parameters
> 
> Add helpers to set the link mode and BW parameters. These are required by a
> follow-up patch setting the parameters for a disabled link.
> 
> Signed-off-by: Imre Deak <imre.deak at intel.com>

LGTM,
Reviewed-by: Suraj Kandpal <suraj.kandpal at intel.com>

> ---
>  .../drm/i915/display/intel_dp_link_training.c | 34 +++++++++++++------
> .../drm/i915/display/intel_dp_link_training.h |  6 ++++
>  2 files changed, 29 insertions(+), 11 deletions(-)
> 
> 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 57536ae200b77..214c8858b8a94 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c
> @@ -21,6 +21,8 @@
>   * IN THE SOFTWARE.
>   */
> 
> +#include <drm/display/drm_dp_helper.h>
> +
>  #include "i915_drv.h"
>  #include "intel_display_types.h"
>  #include "intel_dp.h"
> @@ -703,26 +705,28 @@ static bool
> intel_dp_link_max_vswing_reached(struct intel_dp *intel_dp,
>  	return true;
>  }
> 
> -static void
> -intel_dp_update_downspread_ctrl(struct intel_dp *intel_dp,
> -				const struct intel_crtc_state *crtc_state)
> +void intel_dp_link_training_set_mode(struct intel_dp *intel_dp, int
> +link_rate, bool is_vrr)
>  {
>  	u8 link_config[2];
> 
> -	link_config[0] = crtc_state->vrr.flipline ?
> DP_MSA_TIMING_PAR_IGNORE_EN : 0;
> -	link_config[1] = intel_dp_is_uhbr(crtc_state) ?
> +	link_config[0] = is_vrr ? DP_MSA_TIMING_PAR_IGNORE_EN : 0;
> +	link_config[1] = drm_dp_is_uhbr_rate(link_rate) ?
>  			 DP_SET_ANSI_128B132B : DP_SET_ANSI_8B10B;
>  	drm_dp_dpcd_write(&intel_dp->aux, DP_DOWNSPREAD_CTRL,
> link_config, 2);  }
> 
> -static void
> -intel_dp_update_link_bw_set(struct intel_dp *intel_dp,
> -			    const struct intel_crtc_state *crtc_state,
> -			    u8 link_bw, u8 rate_select)
> +static void intel_dp_update_downspread_ctrl(struct intel_dp *intel_dp,
> +					    const struct intel_crtc_state
> *crtc_state)
>  {
> -	u8 lane_count = crtc_state->lane_count;
> +	intel_dp_link_training_set_mode(intel_dp,
> +					crtc_state->port_clock, crtc_state-
> >vrr.flipline); }
> 
> -	if (crtc_state->enhanced_framing)
> +void intel_dp_link_training_set_bw(struct intel_dp *intel_dp,
> +				   int link_bw, int rate_select, int lane_count,
> +				   bool enhanced_framing)
> +{
> +	if (enhanced_framing)
>  		lane_count |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
> 
>  	if (link_bw) {
> @@ -746,6 +750,14 @@ intel_dp_update_link_bw_set(struct intel_dp
> *intel_dp,
>  	}
>  }
> 
> +static void intel_dp_update_link_bw_set(struct intel_dp *intel_dp,
> +					const struct intel_crtc_state *crtc_state,
> +					u8 link_bw, u8 rate_select)
> +{
> +	intel_dp_link_training_set_bw(intel_dp, link_bw, rate_select, crtc_state-
> >lane_count,
> +				      crtc_state->enhanced_framing); }
> +
>  /*
>   * Prepare link training by configuring the link parameters. On DDI platforms
>   * also enable the port here.
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_link_training.h
> b/drivers/gpu/drm/i915/display/intel_dp_link_training.h
> index 42e7fc6cb171a..2066b91467622 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_link_training.h
> +++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.h
> @@ -16,6 +16,12 @@ struct intel_dp;
>  int intel_dp_read_dprx_caps(struct intel_dp *intel_dp, u8
> dpcd[DP_RECEIVER_CAP_SIZE]);  int intel_dp_init_lttpr_and_dprx_caps(struct
> intel_dp *intel_dp);
> 
> +void intel_dp_link_training_set_mode(struct intel_dp *intel_dp,
> +				     int link_rate, bool is_vrr);
> +void intel_dp_link_training_set_bw(struct intel_dp *intel_dp,
> +				   int link_bw, int rate_select, int lane_count,
> +				   bool enhanced_framing);
> +
>  void intel_dp_get_adjust_train(struct intel_dp *intel_dp,
>  			       const struct intel_crtc_state *crtc_state,
>  			       enum drm_dp_phy dp_phy,
> --
> 2.44.2