[PATCH 21/22] drm/i915: Allow bigjoiner for MST

[Murthy, Arun R]

> -----Original Message-----
> From: Intel-gfx <intel-gfx-bounces at lists.freedesktop.org> On Behalf Of Ville
> Syrjala
> Sent: Friday, March 29, 2024 6:43 AM
> To: intel-gfx at lists.freedesktop.org
> Cc: Manasi Navare <navaremanasi at chromium.org>; Ville Syrjälä
> <ville.syrjala at linux.intel.com>
> Subject: [PATCH 21/22] drm/i915: Allow bigjoiner for MST
> 
> From: Vidya Srinivas <vidya.srinivas at intel.com>
> 
> We need bigjoiner support with MST functionality for MST monitor resolutions
> > 5K to work.
> Adding support for the same.
> 
> v2: Addressed review comments from Jani.
> Revert rejection of MST bigjoiner modes and add functionality
> 
> v3: Fixed pipe_mismatch WARN for mst_master_transcoder
> Credits-to: Manasi Navare <navaremanasi at chromium.org>
> 
> v4: Utilize intel_crtc_joined_pipe_mask() also for handling
>     bigjoiner slave pipes for MST case(Stan)
> [v5: vsyrjala: chunked the modeset squence stuff out,
>                removed bogus mst master transcoder hack,
> 	       keep mgr_lock near the full_pbn check]
> 
> Signed-off-by: Vidya Srinivas <vidya.srinivas at intel.com>
> Reviewed-by: Manasi Navare <navaremanasi at chromium.org>
> Co-developed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
Reviewed-by: Arun R Murthy <arun.r.murthy at intel.com>

Thanks and Regards,
Arun R Murthy
-------------------

>  drivers/gpu/drm/i915/display/intel_dp_mst.c | 25 ++++++++++++---------
>  1 file changed, 14 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> index 2d601d214915..c1530c01f541 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> @@ -525,6 +525,7 @@ static int intel_dp_mst_compute_config(struct
> intel_encoder *encoder,  {
>  	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
>  	struct intel_atomic_state *state = to_intel_atomic_state(conn_state-
> >state);
> +	struct intel_crtc *crtc = to_intel_crtc(pipe_config->uapi.crtc);
>  	struct intel_dp_mst_encoder *intel_mst = enc_to_mst(encoder);
>  	struct intel_dp *intel_dp = &intel_mst->primary->dp;
>  	struct intel_connector *connector =
> @@ -542,6 +543,11 @@ static int intel_dp_mst_compute_config(struct
> intel_encoder *encoder,
>  	if (adjusted_mode->flags & DRM_MODE_FLAG_DBLSCAN)
>  		return -EINVAL;
> 
> +	if (intel_dp_need_bigjoiner(intel_dp, connector,
> +				    adjusted_mode->crtc_hdisplay,
> +				    adjusted_mode->crtc_clock))
> +		pipe_config->bigjoiner_pipes = GENMASK(crtc->pipe + 1, crtc-
> >pipe);
> +
>  	pipe_config->sink_format = INTEL_OUTPUT_FORMAT_RGB;
>  	pipe_config->output_format = INTEL_OUTPUT_FORMAT_RGB;
>  	pipe_config->has_pch_encoder = false;
> @@ -1341,10 +1347,6 @@ intel_dp_mst_mode_valid_ctx(struct
> drm_connector *connector,
>  					       max_link_clock, max_lanes);
>  	mode_rate = intel_dp_link_required(mode->clock, min_bpp);
> 
> -	ret = drm_modeset_lock(&mgr->base.lock, ctx);
> -	if (ret)
> -		return ret;
> -
>  	/*
>  	 * TODO:
>  	 * - Also check if compression would allow for the mode @@ -1357,17
> +1359,18 @@ intel_dp_mst_mode_valid_ctx(struct drm_connector *connector,
>  	 *   corresponding link capabilities of the sink) in case the
>  	 *   stream is uncompressed for it by the last branch device.
>  	 */
> -	if (mode_rate > max_rate || mode->clock > max_dotclk ||
> -	    drm_dp_calc_pbn_mode(mode->clock, min_bpp << 4) > port-
> >full_pbn) {
> -		*status = MODE_CLOCK_HIGH;
> -		return 0;
> -	}
>  	if (intel_dp_need_bigjoiner(intel_dp, intel_connector,
>  				    mode->hdisplay, target_clock)) {
>  		bigjoiner = true;
>  		max_dotclk *= 2;
> +	}
> 
> -		/* TODO: add support for bigjoiner */
> +	ret = drm_modeset_lock(&mgr->base.lock, ctx);
> +	if (ret)
> +		return ret;
> +
> +	if (mode_rate > max_rate || mode->clock > max_dotclk ||
> +	    drm_dp_calc_pbn_mode(mode->clock, min_bpp << 4) > port-
> >full_pbn)
> +{
>  		*status = MODE_CLOCK_HIGH;
>  		return 0;
>  	}
> @@ -1410,7 +1413,7 @@ intel_dp_mst_mode_valid_ctx(struct drm_connector
> *connector,
>  		return 0;
>  	}
> 
> -	*status = intel_mode_valid_max_plane_size(dev_priv, mode, false);
> +	*status = intel_mode_valid_max_plane_size(dev_priv, mode, bigjoiner);
>  	return 0;
>  }
> 
> --
> 2.43.2