[PATCH 3/8] drm/i915/display: Consider fractional vdsc bpp while computing m_n values

[Suraj Kandpal]

From: Ankit Nautiyal <ankit.k.nautiyal at intel.com>

MTL+ supports fractional compressed bits_per_pixel, with precision of
1/16. This compressed bpp is stored in U6.4 format.
Accommodate this precision while computing m_n values.

Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
Reviewed-by: Suraj Kandpal <suraj.kandpal at intel.com>
---
 drivers/gpu/drm/i915/display/intel_display.c | 6 +++++-
 drivers/gpu/drm/i915/display/intel_display.h | 2 +-
 drivers/gpu/drm/i915/display/intel_dp.c      | 5 +++--
 drivers/gpu/drm/i915/display/intel_dp_mst.c  | 6 ++++--
 drivers/gpu/drm/i915/display/intel_fdi.c     | 2 +-
 5 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index a317ef585ffb..3c5b9706ef07 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -2380,10 +2380,14 @@ void
 intel_link_compute_m_n(u16 bits_per_pixel, int nlanes,
 		       int pixel_clock, int link_clock,
 		       struct intel_link_m_n *m_n,
-		       bool fec_enable)
+		       bool fec_enable,
+		       bool is_dsc_fractional_bpp)
 {
 	u32 data_clock = bits_per_pixel * pixel_clock;
 
+	if (is_dsc_fractional_bpp)
+		data_clock = DIV_ROUND_UP(bits_per_pixel * pixel_clock, 16);
+
 	if (fec_enable)
 		data_clock = intel_dp_mode_to_fec_clock(data_clock);
 
diff --git a/drivers/gpu/drm/i915/display/intel_display.h b/drivers/gpu/drm/i915/display/intel_display.h
index 49ac8473b988..a4c4ca3cad65 100644
--- a/drivers/gpu/drm/i915/display/intel_display.h
+++ b/drivers/gpu/drm/i915/display/intel_display.h
@@ -398,7 +398,7 @@ u8 intel_calc_active_pipes(struct intel_atomic_state *state,
 void intel_link_compute_m_n(u16 bpp, int nlanes,
 			    int pixel_clock, int link_clock,
 			    struct intel_link_m_n *m_n,
-			    bool fec_enable);
+			    bool fec_enable, bool is_dsc_fractional_bpp);
 u32 intel_plane_fb_max_stride(struct drm_i915_private *dev_priv,
 			      u32 pixel_format, u64 modifier);
 enum drm_mode_status
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 2a7cbb8dc969..4f56913cabac 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -2562,7 +2562,7 @@ intel_dp_drrs_compute_config(struct intel_connector *connector,
 
 	intel_link_compute_m_n(link_bpp, pipe_config->lane_count, pixel_clock,
 			       pipe_config->port_clock, &pipe_config->dp_m2_n2,
-			       pipe_config->fec_enable);
+			       pipe_config->fec_enable, false);
 
 	/* FIXME: abstract this better */
 	if (pipe_config->splitter.enable)
@@ -2744,7 +2744,8 @@ intel_dp_compute_config(struct intel_encoder *encoder,
 			       adjusted_mode->crtc_clock,
 			       pipe_config->port_clock,
 			       &pipe_config->dp_m_n,
-			       pipe_config->fec_enable);
+			       pipe_config->fec_enable,
+			       pipe_config->dsc.compression_enable);
 
 	/* FIXME: abstract this better */
 	if (pipe_config->splitter.enable)
diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
index 7bf0b6e4ac0b..8f6bd54532cb 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
@@ -172,7 +172,8 @@ static int intel_dp_mst_compute_link_config(struct intel_encoder *encoder,
 			       adjusted_mode->crtc_clock,
 			       crtc_state->port_clock,
 			       &crtc_state->dp_m_n,
-			       crtc_state->fec_enable);
+			       crtc_state->fec_enable,
+			       false);
 	crtc_state->dp_m_n.tu = slots;
 
 	return 0;
@@ -269,7 +270,8 @@ static int intel_dp_dsc_mst_compute_link_config(struct intel_encoder *encoder,
 			       adjusted_mode->crtc_clock,
 			       crtc_state->port_clock,
 			       &crtc_state->dp_m_n,
-			       crtc_state->fec_enable);
+			       crtc_state->fec_enable,
+			       crtc_state->dsc.compression_enable);
 	crtc_state->dp_m_n.tu = slots;
 
 	return 0;
diff --git a/drivers/gpu/drm/i915/display/intel_fdi.c b/drivers/gpu/drm/i915/display/intel_fdi.c
index 4d7d524c6801..3103ea881059 100644
--- a/drivers/gpu/drm/i915/display/intel_fdi.c
+++ b/drivers/gpu/drm/i915/display/intel_fdi.c
@@ -259,7 +259,7 @@ int ilk_fdi_compute_config(struct intel_crtc *crtc,
 	pipe_config->fdi_lanes = lane;
 
 	intel_link_compute_m_n(pipe_config->pipe_bpp, lane, fdi_dotclock,
-			       link_bw, &pipe_config->fdi_m_n, false);
+			       link_bw, &pipe_config->fdi_m_n, false, false);
 
 	ret = ilk_check_fdi_lanes(dev, crtc->pipe, pipe_config);
 	if (ret == -EDEADLK)
-- 
2.25.1