diff --git a/drivers/gpu/drm/radeon/radeon_bios.c b/drivers/gpu/drm/radeon/radeon_bios.c
index 3fc5fa1aefd0f57bcea68ef07c65f7f37f456663..229a20f10e2b0c548b02cd5df527b9b72d6fe31a 100644
--- a/drivers/gpu/drm/radeon/radeon_bios.c
+++ b/drivers/gpu/drm/radeon/radeon_bios.c
@@ -331,7 +331,7 @@ static bool avivo_read_disabled_bios(struct radeon_device *rdev)
 
 	seprom_cntl1 = RREG32(RADEON_SEPROM_CNTL1);
 	viph_control = RREG32(RADEON_VIPH_CONTROL);
-	bus_cntl = RREG32(RADEON_BUS_CNTL);
+	bus_cntl = RREG32(RV370_BUS_CNTL);
 	d1vga_control = RREG32(AVIVO_D1VGA_CONTROL);
 	d2vga_control = RREG32(AVIVO_D2VGA_CONTROL);
 	vga_render_control = RREG32(AVIVO_VGA_RENDER_CONTROL);
@@ -350,7 +350,7 @@ static bool avivo_read_disabled_bios(struct radeon_device *rdev)
 	WREG32(RADEON_VIPH_CONTROL, (viph_control & ~RADEON_VIPH_EN));
 
 	/* enable the rom */
-	WREG32(RADEON_BUS_CNTL, (bus_cntl & ~RADEON_BUS_BIOS_DIS_ROM));
+	WREG32(RV370_BUS_CNTL, (bus_cntl & ~RV370_BUS_BIOS_DIS_ROM));
 
 	/* Disable VGA mode */
 	WREG32(AVIVO_D1VGA_CONTROL,
@@ -367,7 +367,7 @@ static bool avivo_read_disabled_bios(struct radeon_device *rdev)
 	/* restore regs */
 	WREG32(RADEON_SEPROM_CNTL1, seprom_cntl1);
 	WREG32(RADEON_VIPH_CONTROL, viph_control);
-	WREG32(RADEON_BUS_CNTL, bus_cntl);
+	WREG32(RV370_BUS_CNTL, bus_cntl);
 	WREG32(AVIVO_D1VGA_CONTROL, d1vga_control);
 	WREG32(AVIVO_D2VGA_CONTROL, d2vga_control);
 	WREG32(AVIVO_VGA_RENDER_CONTROL, vga_render_control);
@@ -390,7 +390,10 @@ static bool legacy_read_disabled_bios(struct radeon_device *rdev)
 
 	seprom_cntl1 = RREG32(RADEON_SEPROM_CNTL1);
 	viph_control = RREG32(RADEON_VIPH_CONTROL);
-	bus_cntl = RREG32(RADEON_BUS_CNTL);
+	if (rdev->flags & RADEON_IS_PCIE)
+		bus_cntl = RREG32(RV370_BUS_CNTL);
+	else
+		bus_cntl = RREG32(RADEON_BUS_CNTL);
 	crtc_gen_cntl = RREG32(RADEON_CRTC_GEN_CNTL);
 	crtc2_gen_cntl = 0;
 	crtc_ext_cntl = RREG32(RADEON_CRTC_EXT_CNTL);
@@ -412,7 +415,10 @@ static bool legacy_read_disabled_bios(struct radeon_device *rdev)
 	WREG32(RADEON_VIPH_CONTROL, (viph_control & ~RADEON_VIPH_EN));
 
 	/* enable the rom */
-	WREG32(RADEON_BUS_CNTL, (bus_cntl & ~RADEON_BUS_BIOS_DIS_ROM));
+	if (rdev->flags & RADEON_IS_PCIE)
+		WREG32(RV370_BUS_CNTL, (bus_cntl & ~RV370_BUS_BIOS_DIS_ROM));
+	else
+		WREG32(RADEON_BUS_CNTL, (bus_cntl & ~RADEON_BUS_BIOS_DIS_ROM));
 
 	/* Turn off mem requests and CRTC for both controllers */
 	WREG32(RADEON_CRTC_GEN_CNTL,
@@ -439,7 +445,10 @@ static bool legacy_read_disabled_bios(struct radeon_device *rdev)
 	/* restore regs */
 	WREG32(RADEON_SEPROM_CNTL1, seprom_cntl1);
 	WREG32(RADEON_VIPH_CONTROL, viph_control);
-	WREG32(RADEON_BUS_CNTL, bus_cntl);
+	if (rdev->flags & RADEON_IS_PCIE)
+		WREG32(RV370_BUS_CNTL, bus_cntl);
+	else
+		WREG32(RADEON_BUS_CNTL, bus_cntl);
 	WREG32(RADEON_CRTC_GEN_CNTL, crtc_gen_cntl);
 	if (!(rdev->flags & RADEON_SINGLE_CRTC)) {
 		WREG32(RADEON_CRTC2_GEN_CNTL, crtc2_gen_cntl);
diff --git a/drivers/gpu/drm/radeon/radeon_reg.h b/drivers/gpu/drm/radeon/radeon_reg.h
index ec93a75369e671c9b9d0b98407ad5c5e901a4eb2..bc44a3d35ec6f49de04a9570e8fa7b51f600523c 100644
--- a/drivers/gpu/drm/radeon/radeon_reg.h
+++ b/drivers/gpu/drm/radeon/radeon_reg.h
@@ -300,6 +300,8 @@
 #       define RADEON_BUS_READ_BURST         (1 << 30)
 #define RADEON_BUS_CNTL1                    0x0034
 #       define RADEON_BUS_WAIT_ON_LOCK_EN    (1 << 4)
+#define RV370_BUS_CNTL                      0x004c
+#       define RV370_BUS_BIOS_DIS_ROM        (1 << 2)
 /* rv370/rv380, rv410, r423/r430/r480, r5xx */
 #define RADEON_MSI_REARM_EN		    0x0160
 #	define RV370_MSI_REARM_EN	     (1 << 0)