[PATCH 14/15] drm/i915/dp: Add intel_dp_dsc_get_slice_config()

[Imre Deak <imre.deak@intel.com>]

Add intel_dp_dsc_get_slice_config() to compute the detailed slice
configuration and determine the slices-per-line value (returned by
intel_dp_dsc_get_slice_count()) using this function.

v2: Fix incorrectly returning false from intel_dp_dsc_min_slice_count()
    due to rebase fail. (Jouni)

Cc: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Jouni Högander <jouni.hogander@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
---
 drivers/gpu/drm/i915/display/intel_dp.c | 31 ++++++++++++++++++++-----
 1 file changed, 25 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 2c50e380fb396..0ea9c4e3b7d35 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -1019,9 +1019,11 @@ static int intel_dp_dsc_min_slice_count(const struct intel_connector *connector,
 	return min_slice_count;
 }
 
-u8 intel_dp_dsc_get_slice_count(const struct intel_connector *connector,
-				int mode_clock, int mode_hdisplay,
-				int num_joined_pipes)
+static bool
+intel_dp_dsc_get_slice_config(const struct intel_connector *connector,
+			      int mode_clock, int mode_hdisplay,
+			      int num_joined_pipes,
+			      struct intel_dsc_slice_config *config_ret)
 {
 	struct intel_display *display = to_intel_display(connector);
 	int min_slice_count =
@@ -1058,8 +1060,11 @@ u8 intel_dp_dsc_get_slice_count(const struct intel_connector *connector,
 		if (mode_hdisplay % slices_per_line)
 			continue;
 
-		if (min_slice_count <= slices_per_line)
-			return slices_per_line;
+		if (min_slice_count <= slices_per_line) {
+			*config_ret = config;
+
+			return true;
+		}
 	}
 
 	/* Print slice count 1,2,4,..24 if bit#0,1,3,..23 is set in the mask. */
@@ -1070,7 +1075,21 @@ u8 intel_dp_dsc_get_slice_count(const struct intel_connector *connector,
 		    min_slice_count,
 		    (int)BITS_PER_TYPE(sink_slice_count_mask), &sink_slice_count_mask);
 
-	return 0;
+	return false;
+}
+
+u8 intel_dp_dsc_get_slice_count(const struct intel_connector *connector,
+				int mode_clock, int mode_hdisplay,
+				int num_joined_pipes)
+{
+	struct intel_dsc_slice_config config;
+
+	if (!intel_dp_dsc_get_slice_config(connector,
+					   mode_clock, mode_hdisplay,
+					   num_joined_pipes, &config))
+		return 0;
+
+	return intel_dsc_line_slice_count(&config);
 }
 
 static bool source_can_output(struct intel_dp *intel_dp,
-- 
2.49.1