Commit b506a8e1 authored by Ankit Nautiyal's avatar Ankit Nautiyal
Browse files

drm/i915/dp_mst: Rework pipe joiner logic in compute_config 



Similar to the DP SST, refactor mst_stream_compute_config() to iterate
over joiner candidates and select the minimal joiner configuration that
satisfies the mode requirements. This prepares the logic for future changes
that will consider DSC slice overhead.

v2:
 - Move the check for dotclock in the new helper and check for both DSC and
   non-DSC case. In case the check fails for non-DSC, fallback to DSC
   configuration. (Imre)
 - Propagate the return value from the core helper:
   mst_stream_compute_link_for_joined_pipes(). (Imre)
v3:
 - Use num_joined_pipes instead of num_pipes. (Imre)
v4:
 - Switch to 'ret == 0' for break condition to match SST code.

Signed-off-by: default avatarAnkit Nautiyal <ankit.k.nautiyal@intel.com>
Reviewed-by: default avatarImre Deak <imre.deak@intel.com>
Link: https://patch.msgid.link/20260202103731.357416-11-ankit.k.nautiyal@intel.com
parent 331a58a6

drivers/gpu/drm/i915/display/intel_dp_mst.c

+32 −11
Original line number Diff line number Diff line
@@ -602,12 +602,16 @@ static int mst_stream_compute_link_for_joined_pipes(struct intel_encoder *encode 
{

	struct intel_display *display = to_intel_display(encoder);

	struct intel_dp *intel_dp = to_primary_dp(encoder);

	const struct drm_display_mode *adjusted_mode =

		&pipe_config->hw.adjusted_mode;

	struct intel_connector *connector =

		to_intel_connector(conn_state->connector);

	int max_dotclk = display->cdclk.max_dotclk_freq;

	struct link_config_limits limits;

	bool dsc_needed, joiner_needs_dsc;

	int ret = 0;



	max_dotclk *= num_joined_pipes;

	joiner_needs_dsc = intel_dp_joiner_needs_dsc(display, num_joined_pipes);



	dsc_needed = joiner_needs_dsc || intel_dp->force_dsc_en ||
@@ -621,7 +625,7 @@ static int mst_stream_compute_link_for_joined_pipes(struct intel_encoder *encode 
		if (ret == -EDEADLK)

			return ret;



		if (ret)

		if (ret || adjusted_mode->clock > max_dotclk)

			dsc_needed = true;

	}
@@ -664,6 +668,9 @@ static int mst_stream_compute_link_for_joined_pipes(struct intel_encoder *encode 
						  pipe_config->dp_m_n.tu);

		if (ret)

			return ret;



		if (adjusted_mode->clock > max_dotclk)

			return -EINVAL;

	}



	if (ret)
@@ -689,7 +696,7 @@ static int mst_stream_compute_config(struct intel_encoder *encoder, 
	const struct drm_display_mode *adjusted_mode =

		&pipe_config->hw.adjusted_mode;

	int num_joined_pipes;

	int ret = 0;

	int ret = -EINVAL;



	if (pipe_config->fec_enable &&

	    !intel_dp_supports_fec(intel_dp, connector, pipe_config))
@@ -702,16 +709,30 @@ static int mst_stream_compute_config(struct intel_encoder *encoder, 
	pipe_config->output_format = INTEL_OUTPUT_FORMAT_RGB;

	pipe_config->has_pch_encoder = false;



	num_joined_pipes = intel_dp_num_joined_pipes(intel_dp, connector,

						     adjusted_mode->crtc_hdisplay,

						     adjusted_mode->crtc_clock);

	for (num_joined_pipes = 1; num_joined_pipes <= I915_MAX_PIPES; num_joined_pipes++) {

		if (connector->force_joined_pipes &&

		    num_joined_pipes != connector->force_joined_pipes)

			continue;



		if (!intel_dp_can_join(display, num_joined_pipes))

			continue;



		if (adjusted_mode->hdisplay >

		    num_joined_pipes * intel_dp_max_hdisplay_per_pipe(display))

			continue;



		if (num_joined_pipes > 1)

		pipe_config->joiner_pipes = GENMASK(crtc->pipe + num_joined_pipes - 1, crtc->pipe);

			pipe_config->joiner_pipes = GENMASK(crtc->pipe + num_joined_pipes - 1,

							    crtc->pipe);



		ret = mst_stream_compute_link_for_joined_pipes(encoder,

							       pipe_config,

							       conn_state,

							       num_joined_pipes);

		if (ret == 0)

			break;

	}



	if (ret)

		return ret;