[PATCH] drm/i915/display: Add WA_14018221282

[Kahola, Mika]

> -----Original Message-----
> From: Intel-xe <intel-xe-bounces at lists.freedesktop.org> On Behalf Of Nemesa
> Garg
> Sent: Thursday, 26 December 2024 8.07
> To: intel-gfx at lists.freedesktop.org; intel-xe at lists.freedesktop.org
> Cc: Garg, Nemesa <nemesa.garg at intel.com>; Vandita Kulkarni
> <vandita.kulkarni at intel.com>
> Subject: [PATCH] drm/i915/display: Add WA_14018221282
> 
> It was observed that the first write to DKL PHY DP Mode register was not taking
> effect, hence rewrite this register.
> 
> v2: Rename function [Mitul]
> v3: Rename function [Jani]
> v4: Add check for display ver 13 [Matt]
> 

Reviewed-by: Mika Kahola <mika.kahola at intel.com>

> Co-developed-by: Vandita Kulkarni <vandita.kulkarni at intel.com>
> Signed-off-by: Vandita Kulkarni <vandita.kulkarni at intel.com>
> Signed-off-by: Nemesa Garg <nemesa.garg at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_ddi.c | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c
> b/drivers/gpu/drm/i915/display/intel_ddi.c
> index 4f9c50996446..112a37a58be3 100644
> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> @@ -2099,10 +2099,21 @@ void intel_ddi_sanitize_encoder_pll_mapping(struct
> intel_encoder *encoder)
>  	encoder->disable_clock(encoder);
>  }
> 
> +static void
> +tgl_dkl_phy_check_and_rewrite(struct drm_i915_private *dev_priv,
> +			      enum tc_port tc_port, u32 ln0, u32 ln1) {
> +	if (ln0 != intel_dkl_phy_read(dev_priv, DKL_DP_MODE(tc_port, 0)))
> +		intel_dkl_phy_write(dev_priv, DKL_DP_MODE(tc_port, 0), ln0);
> +	if (ln1 != intel_dkl_phy_read(dev_priv, DKL_DP_MODE(tc_port, 1)))
> +		intel_dkl_phy_write(dev_priv, DKL_DP_MODE(tc_port, 1), ln1); }
> +
>  static void
>  icl_program_mg_dp_mode(struct intel_digital_port *dig_port,
>  		       const struct intel_crtc_state *crtc_state)  {
> +	struct intel_display *display = to_intel_display(crtc_state);
>  	struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev);
>  	enum tc_port tc_port = intel_encoder_to_tc(&dig_port->base);
>  	u32 ln0, ln1, pin_assignment;
> @@ -2180,6 +2191,10 @@ icl_program_mg_dp_mode(struct intel_digital_port
> *dig_port,
>  	if (DISPLAY_VER(dev_priv) >= 12) {
>  		intel_dkl_phy_write(dev_priv, DKL_DP_MODE(tc_port, 0), ln0);
>  		intel_dkl_phy_write(dev_priv, DKL_DP_MODE(tc_port, 1), ln1);
> +		 /* WA_14018221282 */
> +		if (IS_DISPLAY_VER(display, 12, 13))
> +			tgl_dkl_phy_check_and_rewrite(dev_priv, tc_port, ln0,
> ln1);
> +
>  	} else {
>  		intel_de_write(dev_priv, MG_DP_MODE(0, tc_port), ln0);
>  		intel_de_write(dev_priv, MG_DP_MODE(1, tc_port), ln1);
> --
> 2.25.1