diff --git a/drivers/gpu/drm/ast/ast_drv.h b/drivers/gpu/drm/ast/ast_drv.h
index 01ef0c0d5db7d..4e3a88f8a85ca 100644
--- a/drivers/gpu/drm/ast/ast_drv.h
+++ b/drivers/gpu/drm/ast/ast_drv.h
@@ -207,6 +207,7 @@ struct ast_device {
 
 	bool support_wsxga_p; /* 1680x1050 */
 	bool support_fullhd; /* 1920x1080 */
+	bool support_wuxga; /* 1920x1200 */
 
 	u8 *dp501_fw_addr;
 	const struct firmware *dp501_fw;	/* dp501 fw */
diff --git a/drivers/gpu/drm/ast/ast_main.c b/drivers/gpu/drm/ast/ast_main.c
index e6237ba92cce3..1de6f1129e165 100644
--- a/drivers/gpu/drm/ast/ast_main.c
+++ b/drivers/gpu/drm/ast/ast_main.c
@@ -38,14 +38,18 @@
 
 static void ast_detect_widescreen(struct ast_device *ast)
 {
-	u8 vgacrd0;
+	u8 vgacrd0, vgacrd1;
 
 	ast->support_wsxga_p = false;
 	ast->support_fullhd = false;
+	ast->support_wuxga = false;
 
 	if (AST_GEN(ast) >= 7) {
 		ast->support_wsxga_p = true;
 		ast->support_fullhd = true;
+		vgacrd1 = ast_get_index_reg(ast, AST_IO_VGACRI, 0xd1);
+		if (!(vgacrd1 & AST_IO_VGACRD1_SUPPORTS_WUXGA))
+			ast->support_wuxga = true;
 	} else if (AST_GEN(ast) >= 6) {
 		vgacrd0 = ast_get_index_reg(ast, AST_IO_VGACRI, 0xd0);
 		if (!(vgacrd0 & AST_IO_VGACRD0_VRAM_INIT_BY_BMC))
@@ -56,6 +60,11 @@ static void ast_detect_widescreen(struct ast_device *ast)
 			ast->support_wsxga_p = true;
 		if (ast->support_wsxga_p)
 			ast->support_fullhd = true;
+		if (ast->support_fullhd) {
+			vgacrd1 = ast_get_index_reg(ast, AST_IO_VGACRI, 0xd1);
+			if (!(vgacrd1 & AST_IO_VGACRD1_SUPPORTS_WUXGA))
+				ast->support_wuxga = true;
+		}
 	} else if (AST_GEN(ast) >= 5) {
 		vgacrd0 = ast_get_index_reg(ast, AST_IO_VGACRI, 0xd0);
 		if (!(vgacrd0 & AST_IO_VGACRD0_VRAM_INIT_BY_BMC))
@@ -66,6 +75,11 @@ static void ast_detect_widescreen(struct ast_device *ast)
 			ast->support_wsxga_p = true;
 		if (ast->support_wsxga_p)
 			ast->support_fullhd = true;
+		if (ast->support_fullhd) {
+			vgacrd1 = ast_get_index_reg(ast, AST_IO_VGACRI, 0xd1);
+			if (!(vgacrd1 & AST_IO_VGACRD1_SUPPORTS_WUXGA))
+				ast->support_wuxga = true;
+		}
 	} else if (AST_GEN(ast) >= 4) {
 		vgacrd0 = ast_get_index_reg(ast, AST_IO_VGACRI, 0xd0);
 		if (!(vgacrd0 & AST_IO_VGACRD0_VRAM_INIT_BY_BMC))
@@ -76,6 +90,11 @@ static void ast_detect_widescreen(struct ast_device *ast)
 			ast->support_wsxga_p = true;
 		if (ast->support_wsxga_p)
 			ast->support_fullhd = true;
+		if (ast->support_fullhd) {
+			vgacrd1 = ast_get_index_reg(ast, AST_IO_VGACRI, 0xd1);
+			if (!(vgacrd1 & AST_IO_VGACRD1_SUPPORTS_WUXGA))
+				ast->support_wuxga = true;
+		}
 	} else if (AST_GEN(ast) >= 3) {
 		vgacrd0 = ast_get_index_reg(ast, AST_IO_VGACRI, 0xd0);
 		if (!(vgacrd0 & AST_IO_VGACRD0_VRAM_INIT_BY_BMC))
@@ -86,6 +105,11 @@ static void ast_detect_widescreen(struct ast_device *ast)
 			if (ast->chip == AST2200)
 				ast->support_fullhd = true;
 		}
+		if (ast->support_fullhd) {
+			vgacrd1 = ast_get_index_reg(ast, AST_IO_VGACRI, 0xd1);
+			if (!(vgacrd1 & AST_IO_VGACRD1_SUPPORTS_WUXGA))
+				ast->support_wuxga = true;
+		}
 	} else if (AST_GEN(ast) >= 2) {
 		vgacrd0 = ast_get_index_reg(ast, AST_IO_VGACRI, 0xd0);
 		if (!(vgacrd0 & AST_IO_VGACRD0_VRAM_INIT_BY_BMC))
@@ -96,6 +120,11 @@ static void ast_detect_widescreen(struct ast_device *ast)
 			if (ast->chip == AST2100)
 				ast->support_fullhd = true;
 		}
+		if (ast->support_fullhd) {
+			vgacrd1 = ast_get_index_reg(ast, AST_IO_VGACRI, 0xd1);
+			if (!(vgacrd1 & AST_IO_VGACRD1_SUPPORTS_WUXGA))
+				ast->support_wuxga = true;
+		}
 	}
 }
 
diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c
index 594a58401cf66..fca625518a873 100644
--- a/drivers/gpu/drm/ast/ast_mode.c
+++ b/drivers/gpu/drm/ast/ast_mode.c
@@ -1022,7 +1022,6 @@ ast_crtc_helper_mode_valid(struct drm_crtc *crtc, const struct drm_display_mode
 {
 	struct ast_device *ast = to_ast_device(crtc->dev);
 	enum drm_mode_status status;
-	uint32_t jtemp;
 
 	if (ast->support_wsxga_p) {
 		if ((mode->hdisplay == 1680) && (mode->vdisplay == 1050))
@@ -1041,11 +1040,10 @@ ast_crtc_helper_mode_valid(struct drm_crtc *crtc, const struct drm_display_mode
 				return MODE_OK;
 
 			if ((mode->hdisplay == 1920) && (mode->vdisplay == 1200)) {
-				jtemp = ast_get_index_reg_mask(ast, AST_IO_VGACRI, 0xd1, 0xff);
-				if (jtemp & 0x01)
-					return MODE_NOMODE;
-				else
+				if (ast->support_wuxga)
 					return MODE_OK;
+				else
+					return MODE_NOMODE;
 			}
 		}
 	}
diff --git a/drivers/gpu/drm/ast/ast_reg.h b/drivers/gpu/drm/ast/ast_reg.h
index b4ff38949a565..9db0d584652a4 100644
--- a/drivers/gpu/drm/ast/ast_reg.h
+++ b/drivers/gpu/drm/ast/ast_reg.h
@@ -55,6 +55,7 @@
 #define AST_IO_VGACRD1_TX_ANX9807_VBIOS		0x0a
 #define AST_IO_VGACRD1_TX_FW_EMBEDDED_FW	0x0c /* special case of DP501 */
 #define AST_IO_VGACRD1_TX_ASTDP			0x0e
+#define AST_IO_VGACRD1_SUPPORTS_WUXGA		BIT(0)
 
 #define AST_IO_VGACRD7_EDID_VALID_FLAG	BIT(0)
 #define AST_IO_VGACRDC_LINK_SUCCESS	BIT(0)
