diff --git a/drivers/gpu/drm/ast/ast_drv.h b/drivers/gpu/drm/ast/ast_drv.h
index 3bedcf7..3fd9d6e 100644
--- a/drivers/gpu/drm/ast/ast_drv.h
+++ b/drivers/gpu/drm/ast/ast_drv.h
@@ -304,8 +304,8 @@ struct ast_vbios_dclk_info {
 };
 
 struct ast_vbios_mode_info {
-	struct ast_vbios_stdtable *std_table;
-	struct ast_vbios_enhtable *enh_table;
+	const struct ast_vbios_stdtable *std_table;
+	const struct ast_vbios_enhtable *enh_table;
 };
 
 extern int ast_mode_init(struct drm_device *dev);
diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c
index e26c98f..1ff596e 100644
--- a/drivers/gpu/drm/ast/ast_mode.c
+++ b/drivers/gpu/drm/ast/ast_mode.c
@@ -80,9 +80,9 @@ static bool ast_get_vbios_mode_info(struct drm_crtc *crtc, struct drm_display_mo
 {
 	struct ast_private *ast = crtc->dev->dev_private;
 	u32 refresh_rate_index = 0, mode_id, color_index, refresh_rate;
+	const struct ast_vbios_enhtable *best = NULL;
 	u32 hborder, vborder;
 	bool check_sync;
-	struct ast_vbios_enhtable *best = NULL;
 
 	switch (crtc->primary->fb->bits_per_pixel) {
 	case 8:
@@ -146,7 +146,7 @@ static bool ast_get_vbios_mode_info(struct drm_crtc *crtc, struct drm_display_mo
 	refresh_rate = drm_mode_vrefresh(mode);
 	check_sync = vbios_mode->enh_table->flags & WideScreenMode;
 	do {
-		struct ast_vbios_enhtable *loop = vbios_mode->enh_table;
+		const struct ast_vbios_enhtable *loop = vbios_mode->enh_table;
 
 		while (loop->refresh_rate != 0xff) {
 			if ((check_sync) &&
@@ -225,7 +225,7 @@ static void ast_set_std_reg(struct drm_crtc *crtc, struct drm_display_mode *mode
 			    struct ast_vbios_mode_info *vbios_mode)
 {
 	struct ast_private *ast = crtc->dev->dev_private;
-	struct ast_vbios_stdtable *stdtable;
+	const struct ast_vbios_stdtable *stdtable;
 	u32 i;
 	u8 jreg;
 
@@ -381,7 +381,7 @@ static void ast_set_dclk_reg(struct drm_device *dev, struct drm_display_mode *mo
 			     struct ast_vbios_mode_info *vbios_mode)
 {
 	struct ast_private *ast = dev->dev_private;
-	struct ast_vbios_dclk_info *clk_info;
+	const struct ast_vbios_dclk_info *clk_info;
 
 	clk_info = &dclk_table[vbios_mode->enh_table->dclk_index];
 
diff --git a/drivers/gpu/drm/ast/ast_tables.h b/drivers/gpu/drm/ast/ast_tables.h
index 3608d5a..a4ddf90 100644
--- a/drivers/gpu/drm/ast/ast_tables.h
+++ b/drivers/gpu/drm/ast/ast_tables.h
@@ -78,37 +78,37 @@
 #define VCLK97_75     		0x19
 #define VCLK118_25			0x1A
 
-static struct ast_vbios_dclk_info dclk_table[] = {
-	{0x2C, 0xE7, 0x03},					/* 00: VCLK25_175	*/
-	{0x95, 0x62, 0x03},				        /* 01: VCLK28_322	*/
-	{0x67, 0x63, 0x01},				        /* 02: VCLK31_5         */
-	{0x76, 0x63, 0x01},				        /* 03: VCLK36         	*/
-	{0xEE, 0x67, 0x01},				        /* 04: VCLK40          	*/
-	{0x82, 0x62, 0x01}, 			        /* 05: VCLK49_5        	*/
-	{0xC6, 0x64, 0x01},                        	        /* 06: VCLK50          	*/
-	{0x94, 0x62, 0x01},                        	        /* 07: VCLK56_25       	*/
-	{0x80, 0x64, 0x00},                        	        /* 08: VCLK65		*/
-	{0x7B, 0x63, 0x00},                        	        /* 09: VCLK75	        */
-	{0x67, 0x62, 0x00},				        /* 0A: VCLK78_75       	*/
-	{0x7C, 0x62, 0x00},                        	        /* 0B: VCLK94_5        	*/
-	{0x8E, 0x62, 0x00},                        	        /* 0C: VCLK108         	*/
-	{0x85, 0x24, 0x00},                        	        /* 0D: VCLK135         	*/
-	{0x67, 0x22, 0x00},                        	        /* 0E: VCLK157_5       	*/
-	{0x6A, 0x22, 0x00},				        /* 0F: VCLK162         	*/
-	{0x4d, 0x4c, 0x80},				        /* 10: VCLK154      	*/
-	{0xa7, 0x78, 0x80},					/* 11: VCLK83.5         */
-	{0x28, 0x49, 0x80},					/* 12: VCLK106.5        */
-	{0x37, 0x49, 0x80},					/* 13: VCLK146.25       */
-	{0x1f, 0x45, 0x80},					/* 14: VCLK148.5        */
-	{0x47, 0x6c, 0x80},					/* 15: VCLK71       */
-	{0x25, 0x65, 0x80},					/* 16: VCLK88.75    */
-	{0x77, 0x58, 0x80},					/* 17: VCLK119      */
-	{0x32, 0x67, 0x80},				    /* 18: VCLK85_5     */
-	{0x6a, 0x6d, 0x80},					/* 19: VCLK97_75	*/
-	{0x3b, 0x2c, 0x81},					/* 1A: VCLK118_25	*/
+static const struct ast_vbios_dclk_info dclk_table[] = {
+	{0x2C, 0xE7, 0x03},			/* 00: VCLK25_175	*/
+	{0x95, 0x62, 0x03},			/* 01: VCLK28_322	*/
+	{0x67, 0x63, 0x01},			/* 02: VCLK31_5		*/
+	{0x76, 0x63, 0x01},			/* 03: VCLK36		*/
+	{0xEE, 0x67, 0x01},			/* 04: VCLK40		*/
+	{0x82, 0x62, 0x01},			/* 05: VCLK49_5		*/
+	{0xC6, 0x64, 0x01},			/* 06: VCLK50		*/
+	{0x94, 0x62, 0x01},			/* 07: VCLK56_25	*/
+	{0x80, 0x64, 0x00},			/* 08: VCLK65		*/
+	{0x7B, 0x63, 0x00},			/* 09: VCLK75		*/
+	{0x67, 0x62, 0x00},			/* 0A: VCLK78_75	*/
+	{0x7C, 0x62, 0x00},			/* 0B: VCLK94_5		*/
+	{0x8E, 0x62, 0x00},			/* 0C: VCLK108		*/
+	{0x85, 0x24, 0x00},			/* 0D: VCLK135		*/
+	{0x67, 0x22, 0x00},			/* 0E: VCLK157_5	*/
+	{0x6A, 0x22, 0x00},			/* 0F: VCLK162		*/
+	{0x4d, 0x4c, 0x80},			/* 10: VCLK154		*/
+	{0xa7, 0x78, 0x80},			/* 11: VCLK83.5		*/
+	{0x28, 0x49, 0x80},			/* 12: VCLK106.5	*/
+	{0x37, 0x49, 0x80},			/* 13: VCLK146.25	*/
+	{0x1f, 0x45, 0x80},			/* 14: VCLK148.5	*/
+	{0x47, 0x6c, 0x80},			/* 15: VCLK71		*/
+	{0x25, 0x65, 0x80},			/* 16: VCLK88.75	*/
+	{0x77, 0x58, 0x80},			/* 17: VCLK119		*/
+	{0x32, 0x67, 0x80},			/* 18: VCLK85_5		*/
+	{0x6a, 0x6d, 0x80},			/* 19: VCLK97_75	*/
+	{0x3b, 0x2c, 0x81},			/* 1A: VCLK118_25	*/
 };
 
-static struct ast_vbios_stdtable vbios_stdtable[] = {
+static const struct ast_vbios_stdtable vbios_stdtable[] = {
 	/* MD_2_3_400 */
 	{
 		0x67,
@@ -181,21 +181,21 @@ static struct ast_vbios_stdtable vbios_stdtable[] = {
 	},
 };
 
-static struct ast_vbios_enhtable res_640x480[] = {
+static const struct ast_vbios_enhtable res_640x480[] = {
 	{ 800, 640, 8, 96, 525, 480, 2, 2, VCLK25_175,	/* 60Hz */
 	  (SyncNN | HBorder | VBorder | Charx8Dot), 60, 1, 0x2E },
 	{ 832, 640, 16, 40, 520, 480, 1, 3, VCLK31_5,	/* 72Hz */
 	  (SyncNN | HBorder | VBorder | Charx8Dot), 72, 2, 0x2E  },
 	{ 840, 640, 16, 64, 500, 480, 1, 3, VCLK31_5,	/* 75Hz */
 	  (SyncNN | Charx8Dot) , 75, 3, 0x2E },
-	{ 832, 640, 56, 56, 509, 480, 1, 3, VCLK36,		/* 85Hz */
+	{ 832, 640, 56, 56, 509, 480, 1, 3, VCLK36,	/* 85Hz */
 	  (SyncNN | Charx8Dot) , 85, 4, 0x2E },
-	{ 832, 640, 56, 56, 509, 480, 1, 3, VCLK36,		/* end */
+	{ 832, 640, 56, 56, 509, 480, 1, 3, VCLK36,	/* end */
 	  (SyncNN | Charx8Dot) , 0xFF, 4, 0x2E },
 };
 
-static struct ast_vbios_enhtable res_800x600[] = {
-	{1024, 800, 24, 72, 625, 600, 1, 2, VCLK36,		/* 56Hz */
+static const struct ast_vbios_enhtable res_800x600[] = {
+	{1024, 800, 24, 72, 625, 600, 1, 2, VCLK36,	/* 56Hz */
 	 (SyncPP | Charx8Dot), 56, 1, 0x30 },
 	{1056, 800, 40, 128, 628, 600, 1, 4, VCLK40,	/* 60Hz */
 	 (SyncPP | Charx8Dot), 60, 2, 0x30 },
@@ -210,7 +210,7 @@ static struct ast_vbios_enhtable res_800x600[] = {
 };
 
 
-static struct ast_vbios_enhtable res_1024x768[] = {
+static const struct ast_vbios_enhtable res_1024x768[] = {
 	{1344, 1024, 24, 136, 806, 768, 3, 6, VCLK65,	/* 60Hz */
 	 (SyncNN | Charx8Dot), 60, 1, 0x31 },
 	{1328, 1024, 24, 136, 806, 768, 3, 6, VCLK75,	/* 70Hz */
@@ -223,7 +223,7 @@ static struct ast_vbios_enhtable res_1024x768[] = {
 	 (SyncPP | Charx8Dot), 0xFF, 4, 0x31 },
 };
 
-static struct ast_vbios_enhtable res_1280x1024[] = {
+static const struct ast_vbios_enhtable res_1280x1024[] = {
 	{1688, 1280, 48, 112, 1066, 1024, 1, 3, VCLK108,	/* 60Hz */
 	 (SyncPP | Charx8Dot), 60, 1, 0x32 },
 	{1688, 1280, 16, 144, 1066, 1024, 1, 3, VCLK135,	/* 75Hz */
@@ -234,7 +234,7 @@ static struct ast_vbios_enhtable res_1280x1024[] = {
 	 (SyncPP | Charx8Dot), 0xFF, 3, 0x32 },
 };
 
-static struct ast_vbios_enhtable res_1600x1200[] = {
+static const struct ast_vbios_enhtable res_1600x1200[] = {
 	{2160, 1600, 64, 192, 1250, 1200, 1, 3, VCLK162,	/* 60Hz */
 	 (SyncPP | Charx8Dot), 60, 1, 0x33 },
 	{2160, 1600, 64, 192, 1250, 1200, 1, 3, VCLK162,	/* end */
@@ -242,23 +242,23 @@ static struct ast_vbios_enhtable res_1600x1200[] = {
 };
 
 /* 16:9 */
-static struct ast_vbios_enhtable res_1360x768[] = {
-	{1792, 1360, 64,112, 795,  768, 3, 6, VCLK85_5,	         /* 60Hz */
+static const struct ast_vbios_enhtable res_1360x768[] = {
+	{1792, 1360, 64, 112, 795, 768, 3, 6, VCLK85_5,		/* 60Hz */
 	 (SyncPP | Charx8Dot | LineCompareOff | WideScreenMode | NewModeInfo), 60, 1, 0x39 },
-	{1792, 1360, 64,112, 795,  768, 3, 6, VCLK85_5,	         /* end */
+	{1792, 1360, 64, 112, 795, 768, 3, 6, VCLK85_5,	         /* end */
 	 (SyncPP | Charx8Dot | LineCompareOff | WideScreenMode | NewModeInfo), 0xFF, 1, 0x39 },
 };
 
-static struct ast_vbios_enhtable res_1600x900[] = {
-	{1760, 1600, 48, 32, 926,  900, 3, 5, VCLK97_75,	/* 60Hz CVT RB */
+static const struct ast_vbios_enhtable res_1600x900[] = {
+	{1760, 1600, 48, 32, 926, 900, 3, 5, VCLK97_75,		/* 60Hz CVT RB */
 	 (SyncNP | Charx8Dot | LineCompareOff | WideScreenMode | NewModeInfo), 60, 1, 0x3A },
-	{2112, 1600, 88,168, 934,  900, 3, 5, VCLK118_25,	/* 60Hz CVT */
+	{2112, 1600, 88, 168, 934, 900, 3, 5, VCLK118_25,	/* 60Hz CVT */
 	 (SyncPN | Charx8Dot | LineCompareOff | WideScreenMode | NewModeInfo), 60, 2, 0x3A },
-	{2112, 1600, 88,168, 934,  900, 3, 5, VCLK118_25,	/* 60Hz CVT */
+	{2112, 1600, 88, 168, 934, 900, 3, 5, VCLK118_25,	/* 60Hz CVT */
 	 (SyncPN | Charx8Dot | LineCompareOff | WideScreenMode | NewModeInfo), 0xFF, 2, 0x3A },
 };
 
-static struct ast_vbios_enhtable res_1920x1080[] = {
+static const struct ast_vbios_enhtable res_1920x1080[] = {
 	{2200, 1920, 88, 44, 1125, 1080, 4, 5, VCLK148_5,	/* 60Hz */
 	 (SyncNP | Charx8Dot | LineCompareOff | WideScreenMode | NewModeInfo), 60, 1, 0x38 },
 	{2200, 1920, 88, 44, 1125, 1080, 4, 5, VCLK148_5,	/* 60Hz */
@@ -267,8 +267,8 @@ static struct ast_vbios_enhtable res_1920x1080[] = {
 
 
 /* 16:10 */
-static struct ast_vbios_enhtable res_1280x800[] = {
-	{1440, 1280, 48, 32,  823,  800, 3, 6, VCLK71,	/* 60Hz RB */
+static const struct ast_vbios_enhtable res_1280x800[] = {
+	{1440, 1280, 48, 32,  823,  800, 3, 6, VCLK71,		/* 60Hz RB */
 	 (SyncNP | Charx8Dot | LineCompareOff | WideScreenMode | NewModeInfo), 60, 1, 0x35 },
 	{1680, 1280, 72,128,  831,  800, 3, 6, VCLK83_5,	/* 60Hz */
 	 (SyncPN | Charx8Dot | LineCompareOff | WideScreenMode | NewModeInfo), 60, 2, 0x35 },
@@ -277,7 +277,7 @@ static struct ast_vbios_enhtable res_1280x800[] = {
 
 };
 
-static struct ast_vbios_enhtable res_1440x900[] = {
+static const struct ast_vbios_enhtable res_1440x900[] = {
 	{1600, 1440, 48, 32,  926,  900, 3, 6, VCLK88_75,	/* 60Hz RB */
 	 (SyncNP | Charx8Dot | LineCompareOff | WideScreenMode | NewModeInfo), 60, 1, 0x36 },
 	{1904, 1440, 80,152,  934,  900, 3, 6, VCLK106_5,	/* 60Hz */
@@ -286,8 +286,8 @@ static struct ast_vbios_enhtable res_1440x900[] = {
 	 (SyncPN | Charx8Dot | LineCompareOff | WideScreenMode | NewModeInfo), 0xFF, 2, 0x36 },
 };
 
-static struct ast_vbios_enhtable res_1680x1050[] = {
-	{1840, 1680, 48, 32, 1080, 1050, 3, 6, VCLK119,	/* 60Hz RB */
+static const struct ast_vbios_enhtable res_1680x1050[] = {
+	{1840, 1680, 48, 32, 1080, 1050, 3, 6, VCLK119,		/* 60Hz RB */
 	 (SyncNP | Charx8Dot | LineCompareOff | WideScreenMode | NewModeInfo), 60, 1, 0x37 },
 	{2240, 1680,104,176, 1089, 1050, 3, 6, VCLK146_25,	/* 60Hz */
 	 (SyncPN | Charx8Dot | LineCompareOff | WideScreenMode | NewModeInfo), 60, 2, 0x37 },
@@ -295,10 +295,10 @@ static struct ast_vbios_enhtable res_1680x1050[] = {
 	 (SyncPN | Charx8Dot | LineCompareOff | WideScreenMode | NewModeInfo), 0xFF, 2, 0x37 },
 };
 
-static struct ast_vbios_enhtable res_1920x1200[] = {
-	{2080, 1920, 48, 32, 1235, 1200, 3, 6, VCLK154,	/* 60Hz RB*/
+static const struct ast_vbios_enhtable res_1920x1200[] = {
+	{2080, 1920, 48, 32, 1235, 1200, 3, 6, VCLK154,		/* 60Hz RB*/
 	 (SyncNP | Charx8Dot | LineCompareOff | WideScreenMode | NewModeInfo), 60, 1, 0x34 },
-	{2080, 1920, 48, 32, 1235, 1200, 3, 6, VCLK154,	/* 60Hz RB */
+	{2080, 1920, 48, 32, 1235, 1200, 3, 6, VCLK154,		/* 60Hz RB */
 	 (SyncNP | Charx8Dot | LineCompareOff | WideScreenMode | NewModeInfo), 0xFF, 1, 0x34 },
 };
 
