drm/amd/display: split TF/LUT colorop state lookups into separate upfront phases

In __set_dm_plane_colorop_shaper and __set_dm_plane_colorop_blend the
single colorop_state variable was reused sequentially: first to capture
the TF state, then (after mutating the colorop pointer) to capture the
LUT state.

Split into separate tf_state / lut_state pointers and introduce a
dedicated lut_colorop local. Resolve both pointers upfront before any
computation begins. This separates the concern of "find the states" from
"use the states" and makes the code easier to follow.

No functional change.

Assisted-by: Copilot:claude-opus-4.8
Reviewed-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: George Zhang <george.zhang@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 48 insertions, 46 deletions

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c
index 60ca4356da9a..9bcb73c95fef 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c
@@ -1640,8 +1640,10 @@ __set_dm_plane_colorop_shaper(struct drm_plane_state *plane_state,
 			      struct drm_colorop *colorop)
 {
 	struct drm_colorop *old_colorop;
-	struct drm_colorop_state *colorop_state = NULL, *new_colorop_state;
+	struct drm_colorop_state *new_colorop_state;
+	struct drm_colorop_state *tf_state = NULL, *lut_state = NULL;
 	struct drm_atomic_commit *state = plane_state->state;
+	struct drm_colorop *lut_colorop;
 	enum dc_transfer_func_predefined default_tf = TRANSFER_FUNCTION_LINEAR;
 	struct dc_transfer_func *tf = &dc_plane_state->cm.shaper_func;
 	const struct drm_color_lut32 *shaper_lut;
@@ -1650,53 +1652,52 @@ __set_dm_plane_colorop_shaper(struct drm_plane_state *plane_state,
 	u32 shaper_size;
 	int i = 0, ret = 0;
 
-	/* 1D Curve - SHAPER TF */
+	/* 1D Curve - SHAPER TF: find state */
 	old_colorop = colorop;
 	for_each_new_colorop_in_state(state, colorop, new_colorop_state, i) {
 		if (new_colorop_state->colorop == old_colorop &&
 		    (BIT(new_colorop_state->curve_1d_type) & amdgpu_dm_supported_shaper_tfs)) {
-			colorop_state = new_colorop_state;
+			tf_state = new_colorop_state;
 			break;
 		}
 	}
 
-	if (colorop_state && !colorop_state->bypass) {
-		drm_dbg(dev, "Shaper TF colorop with ID: %d\n", colorop->base.id);
-		tf->type = TF_TYPE_DISTRIBUTED_POINTS;
-		tf->tf = default_tf = amdgpu_colorop_tf_to_dc_tf(colorop_state->curve_1d_type);
-		tf->sdr_ref_white_level = SDR_WHITE_LEVEL_INIT_VALUE;
-		ret = __set_output_tf(tf, 0, 0, false);
-		if (ret)
-			return ret;
-		enabled = true;
-	}
-
-	/* 1D LUT - SHAPER LUT */
-	colorop = old_colorop->next;
-	if (!colorop) {
+	/* 1D LUT - SHAPER LUT: find state */
+	lut_colorop = old_colorop->next;
+	if (!lut_colorop) {
 		drm_dbg(dev, "no Shaper LUT colorop found\n");
 		return -EINVAL;
 	}
 
-	old_colorop = colorop;
 	for_each_new_colorop_in_state(state, colorop, new_colorop_state, i) {
-		if (new_colorop_state->colorop == old_colorop &&
+		if (new_colorop_state->colorop == lut_colorop &&
 		    new_colorop_state->colorop->type == DRM_COLOROP_1D_LUT) {
-			colorop_state = new_colorop_state;
+			lut_state = new_colorop_state;
 			break;
 		}
 	}
 
-	if (colorop_state && !colorop_state->bypass) {
-		drm_dbg(dev, "Shaper LUT colorop with ID: %d\n", colorop->base.id);
+	if (tf_state && !tf_state->bypass) {
+		drm_dbg(dev, "Shaper TF colorop with ID: %d\n", old_colorop->base.id);
+		tf->type = TF_TYPE_DISTRIBUTED_POINTS;
+		tf->tf = default_tf = amdgpu_colorop_tf_to_dc_tf(tf_state->curve_1d_type);
+		tf->sdr_ref_white_level = SDR_WHITE_LEVEL_INIT_VALUE;
+		ret = __set_output_tf(tf, 0, 0, false);
+		if (ret)
+			return ret;
+		enabled = true;
+	}
+
+	if (lut_state && !lut_state->bypass) {
+		drm_dbg(dev, "Shaper LUT colorop with ID: %d\n", lut_colorop->base.id);
 		tf->type = TF_TYPE_DISTRIBUTED_POINTS;
 		tf->tf = default_tf;
 		tf->sdr_ref_white_level = SDR_WHITE_LEVEL_INIT_VALUE;
-		shaper_lut = __extract_blob_lut32(colorop_state->data, &shaper_size);
+		shaper_lut = __extract_blob_lut32(lut_state->data, &shaper_size);
 		shaper_size = shaper_lut != NULL ? shaper_size : 0;
 
 		/* Custom LUT size must be the same as supported size */
-		if (shaper_size == colorop->size) {
+		if (shaper_size == lut_colorop->size) {
 			ret = __set_output_tf_32(tf, shaper_lut, shaper_size, false);
 			if (ret)
 				return ret;
@@ -1812,8 +1813,10 @@ __set_dm_plane_colorop_blend(struct drm_plane_state *plane_state,
 			     struct drm_colorop *colorop)
 {
 	struct drm_colorop *old_colorop;
-	struct drm_colorop_state *colorop_state = NULL, *new_colorop_state;
+	struct drm_colorop_state *new_colorop_state;
+	struct drm_colorop_state *tf_state = NULL, *lut_state = NULL;
 	struct drm_atomic_commit *state = plane_state->state;
+	struct drm_colorop *lut_colorop;
 	enum dc_transfer_func_predefined default_tf = TRANSFER_FUNCTION_LINEAR;
 	struct dc_transfer_func *tf = &dc_plane_state->cm.blend_func;
 	const struct drm_color_lut32 *blend_lut = NULL;
@@ -1823,52 +1826,51 @@ __set_dm_plane_colorop_blend(struct drm_plane_state *plane_state,
 
 	dc_plane_state->cm.flags.bits.blend_enable = 0;
 
-	/* 1D Curve - BLND TF */
+	/* 1D Curve - BLND TF: find state */
 	old_colorop = colorop;
 	for_each_new_colorop_in_state(state, colorop, new_colorop_state, i) {
 		if (new_colorop_state->colorop == old_colorop &&
 		    (BIT(new_colorop_state->curve_1d_type) & amdgpu_dm_supported_blnd_tfs)) {
-			colorop_state = new_colorop_state;
+			tf_state = new_colorop_state;
 			break;
 		}
 	}
 
-	if (colorop_state && !colorop_state->bypass) {
-		drm_dbg(dev, "Blend TF colorop with ID: %d\n", colorop->base.id);
-		tf->type = TF_TYPE_DISTRIBUTED_POINTS;
-		tf->tf = default_tf = amdgpu_colorop_tf_to_dc_tf(colorop_state->curve_1d_type);
-		tf->sdr_ref_white_level = SDR_WHITE_LEVEL_INIT_VALUE;
-		dc_plane_state->cm.flags.bits.blend_enable = 1;
-		__set_input_tf_32(NULL, tf, blend_lut, blend_size);
-	}
-
-	/* 1D Curve - BLND LUT */
-	colorop = old_colorop->next;
-	if (!colorop) {
+	/* 1D LUT - BLND LUT: find state */
+	lut_colorop = old_colorop->next;
+	if (!lut_colorop) {
 		drm_dbg(dev, "no Blend LUT colorop found\n");
 		return -EINVAL;
 	}
 
-	old_colorop = colorop;
 	for_each_new_colorop_in_state(state, colorop, new_colorop_state, i) {
-		if (new_colorop_state->colorop == old_colorop &&
+		if (new_colorop_state->colorop == lut_colorop &&
 		    new_colorop_state->colorop->type == DRM_COLOROP_1D_LUT) {
-			colorop_state = new_colorop_state;
+			lut_state = new_colorop_state;
 			break;
 		}
 	}
 
-	if (colorop_state && !colorop_state->bypass) {
-		drm_dbg(dev, "Blend LUT colorop with ID: %d\n", colorop->base.id);
+	if (tf_state && !tf_state->bypass) {
+		drm_dbg(dev, "Blend TF colorop with ID: %d\n", old_colorop->base.id);
+		tf->type = TF_TYPE_DISTRIBUTED_POINTS;
+		tf->tf = default_tf = amdgpu_colorop_tf_to_dc_tf(tf_state->curve_1d_type);
+		tf->sdr_ref_white_level = SDR_WHITE_LEVEL_INIT_VALUE;
+		dc_plane_state->cm.flags.bits.blend_enable = 1;
+		__set_input_tf_32(NULL, tf, blend_lut, blend_size);
+	}
+
+	if (lut_state && !lut_state->bypass) {
+		drm_dbg(dev, "Blend LUT colorop with ID: %d\n", lut_colorop->base.id);
 		tf->type = TF_TYPE_DISTRIBUTED_POINTS;
 		tf->tf = default_tf;
 		tf->sdr_ref_white_level = SDR_WHITE_LEVEL_INIT_VALUE;
 		dc_plane_state->cm.flags.bits.blend_enable = 1;
-		blend_lut = __extract_blob_lut32(colorop_state->data, &blend_size);
+		blend_lut = __extract_blob_lut32(lut_state->data, &blend_size);
 		blend_size = blend_lut != NULL ? blend_size : 0;
 
 		/* Custom LUT size must be the same as supported size */
-		if (blend_size == colorop->size)
+		if (blend_size == lut_colorop->size)
 			__set_input_tf_32(NULL, tf, blend_lut, blend_size);
 	}