Re: [Intel-gfx] [PATCH 1/4] drm/i915/cx0: Add intel_cx0_get_owned_lane_mask()

["Taylor, Clinton A" <clinton.a.taylor@intel.com>]

On Tue, 2023-07-25 at 18:27 -0300, Gustavo Sousa wrote:
> There are more parts of C10/C20 programming that need to take owned
> lanes into account. Define the function intel_cx0_get_owned_lane_mask()
> and use it. There will be new users of that function in upcoming
> changes.
> 
> BSpec: 64539
> Signed-off-by: Gustavo Sousa <gustavo.sousa@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_cx0_phy.c | 44 ++++++++++++--------
>  1 file changed, 27 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_cx0_phy.c
> b/drivers/gpu/drm/i915/display/intel_cx0_phy.c
> index 1b00ef2c6185..b903ceb0b56a 100644
> --- a/drivers/gpu/drm/i915/display/intel_cx0_phy.c
> +++ b/drivers/gpu/drm/i915/display/intel_cx0_phy.c
> @@ -46,6 +46,22 @@ static int lane_mask_to_lane(u8 lane_mask)
>  	return ilog2(lane_mask);
>  }
>  
> +static u8 intel_cx0_get_owned_lane_mask(struct drm_i915_private *i915,
> +					struct intel_encoder *encoder)
> +{
> +	struct intel_digital_port *dig_port = enc_to_dig_port(encoder);
> +
> +	if (!intel_tc_port_in_dp_alt_mode(dig_port))
> +		return INTEL_CX0_BOTH_LANES;
> +
> +	/*
> +	 * In DP-alt with pin assignment D, only PHY lane 0 is owned
> +	 * by display and lane 1 is owned by USB.
> +	 */
 lane_revesal is not being handled here. Do we need to take lane_reversal into account
with Pin assignment D is being used?

-Clint

> +	return intel_tc_port_fia_max_lane_count(dig_port) > 2
> +		? INTEL_CX0_BOTH_LANES : INTEL_CX0_LANE0;
> +}
> +
>  static void
>  assert_dc_off(struct drm_i915_private *i915)
>  {
> @@ -2534,17 +2550,15 @@ static void intel_cx0_phy_lane_reset(struct drm_i915_private
> *i915,
>  {
>  	enum port port = encoder->port;
>  	enum phy phy = intel_port_to_phy(i915, port);
> -	bool both_lanes =  intel_tc_port_fia_max_lane_count(enc_to_dig_port(encoder)) > 2;
> -	u8 lane_mask = lane_reversal ? INTEL_CX0_LANE1 :
> -				  INTEL_CX0_LANE0;
> -	u32 lane_pipe_reset = both_lanes ?
> -			      XELPDP_LANE_PIPE_RESET(0) |
> -			      XELPDP_LANE_PIPE_RESET(1) :
> -			      XELPDP_LANE_PIPE_RESET(0);
> -	u32 lane_phy_current_status = both_lanes ?
> -				      XELPDP_LANE_PHY_CURRENT_STATUS(0) |
> -				      XELPDP_LANE_PHY_CURRENT_STATUS(1) :
> -				      XELPDP_LANE_PHY_CURRENT_STATUS(0);
> +	u8 owned_lane_mask = intel_cx0_get_owned_lane_mask(i915, encoder);
> +	u8 lane_mask = lane_reversal ? INTEL_CX0_LANE1 : INTEL_CX0_LANE0;
> +	u32 lane_pipe_reset = owned_lane_mask == INTEL_CX0_BOTH_LANES
> +				? XELPDP_LANE_PIPE_RESET(0) | XELPDP_LANE_PIPE_RESET(1)
> +				: XELPDP_LANE_PIPE_RESET(0);
> +	u32 lane_phy_current_status = owned_lane_mask == INTEL_CX0_BOTH_LANES
> +					? (XELPDP_LANE_PHY_CURRENT_STATUS(0) |
> +					   XELPDP_LANE_PHY_CURRENT_STATUS(1))
> +					: XELPDP_LANE_PHY_CURRENT_STATUS(0);
>  
>  	if (__intel_de_wait_for_register(i915, XELPDP_PORT_BUF_CTL1(port),
>  					 XELPDP_PORT_BUF_SOC_PHY_READY,
> @@ -2564,15 +2578,11 @@ static void intel_cx0_phy_lane_reset(struct drm_i915_private
> *i915,
>  			 phy_name(phy), XELPDP_PORT_RESET_START_TIMEOUT_US);
>  
>  	intel_de_rmw(i915, XELPDP_PORT_CLOCK_CTL(port),
> -		     intel_cx0_get_pclk_refclk_request(both_lanes ?
> -						       INTEL_CX0_BOTH_LANES :
> -						       INTEL_CX0_LANE0),
> +		     intel_cx0_get_pclk_refclk_request(owned_lane_mask),
>  		     intel_cx0_get_pclk_refclk_request(lane_mask));
>  
>  	if (__intel_de_wait_for_register(i915, XELPDP_PORT_CLOCK_CTL(port),
> -					 intel_cx0_get_pclk_refclk_ack(both_lanes ?
> -								       INTEL_CX0_BOTH_LANE
> S :
> -								       INTEL_CX0_LANE0),
> +					 intel_cx0_get_pclk_refclk_ack(owned_lane_mask),
>  					 intel_cx0_get_pclk_refclk_ack(lane_mask),
>  					 XELPDP_REFCLK_ENABLE_TIMEOUT_US, 0, NULL))
>  		drm_warn(&i915->drm, "PHY %c failed to request refclk after %dus.\n",