[PATCH] drm/ast: Fix no display at WayLand after power-off

[Jammy Huang]

With WayLand, there is error log when display waken up from power-off:
gnome-shell: Failed to post KMS update: CRTC property (GAMMA_LUT) not found
gnome-shell: Page flip discarded: CRTC property (GAMMA_LUT) not found

To fix the issue, enable GAMMA_LUT property on CRTC.

Signed-off-by: Jammy Huang <jammy_huang@xxxxxxxxxxxxxx>
---
 drivers/gpu/drm/ast/ast_drv.h  | 2 ++
 drivers/gpu/drm/ast/ast_mode.c | 5 +++--
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/ast/ast_drv.h b/drivers/gpu/drm/ast/ast_drv.h
index 2e44b971c3a6..fd9af1cf0563 100644
--- a/drivers/gpu/drm/ast/ast_drv.h
+++ b/drivers/gpu/drm/ast/ast_drv.h
@@ -86,6 +86,8 @@ enum ast_tx_chip {
 #define AST_DRAM_4Gx16   7
 #define AST_DRAM_8Gx16   8
 
+#define MAX_COLOR_LUT_ENTRIES 256
+
 /*
  * Cursor plane
  */
diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c
index 1bc0220e6783..87bd9697bb44 100644
--- a/drivers/gpu/drm/ast/ast_mode.c
+++ b/drivers/gpu/drm/ast/ast_mode.c
@@ -74,7 +74,7 @@ static void ast_crtc_load_lut(struct ast_private *ast, struct drm_crtc *crtc)
 	g = r + crtc->gamma_size;
 	b = g + crtc->gamma_size;
 
-	for (i = 0; i < 256; i++)
+	for (i = 0; i < MAX_COLOR_LUT_ENTRIES; i++)
 		ast_load_palette_index(ast, i, *r++ >> 8, *g++ >> 8, *b++ >> 8);
 }
 
@@ -1323,7 +1323,8 @@ static int ast_crtc_init(struct drm_device *dev)
 	if (ret)
 		return ret;
 
-	drm_mode_crtc_set_gamma_size(crtc, 256);
+	drm_crtc_enable_color_mgmt(crtc, 0, false, MAX_COLOR_LUT_ENTRIES);
+	drm_mode_crtc_set_gamma_size(crtc, MAX_COLOR_LUT_ENTRIES);
 	drm_crtc_helper_add(crtc, &ast_crtc_helper_funcs);
 
 	return 0;

base-commit: 8ed710da2873c2aeb3bb805864a699affaf1d03b
-- 
2.25.1