diff --git a/openpower/linux/linux-0004-drivers-drm-ast-Switch-SCU-to-VGA-output-on-POST.patch b/openpower/linux/linux-0004-drivers-drm-ast-Switch-SCU-to-VGA-output-on-POST.patch
new file mode 100644
index 0000000..311f35b
--- /dev/null
+++ b/openpower/linux/linux-0004-drivers-drm-ast-Switch-SCU-to-VGA-output-on-POST.patch
@@ -0,0 +1,72 @@
+From c530d7ca1a5e8645b8a8a9496131ff9b6b896450 Mon Sep 17 00:00:00 2001
+From: Jeremy Kerr <jk@ozlabs.org>
+Date: Wed, 2 Mar 2016 11:25:47 +0800
+Subject: [PATCH 4/7] drivers/drm/ast: Switch SCU to VGA output on POST
+
+On AST BMC platforms, the BMC may be using the VGA device for UART
+mirroring. In this case, we need to switch the DAC output to
+VGA mode.
+
+Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
+Signed-off-by: Joel Stanley <joel@jms.id.au>
+---
+ drivers/gpu/drm/ast/ast_post.c | 32 ++++++++++++++++++++++++++++++++
+ 1 file changed, 32 insertions(+)
+
+diff --git a/drivers/gpu/drm/ast/ast_post.c b/drivers/gpu/drm/ast/ast_post.c
+index 810c51d92b99..703dba2ba84b 100644
+--- a/drivers/gpu/drm/ast/ast_post.c
++++ b/drivers/gpu/drm/ast/ast_post.c
+@@ -32,6 +32,7 @@
+ #include "ast_dram_tables.h"
+ 
+ static void ast_init_dram_2300(struct drm_device *dev);
++static void ast_init_output_control(struct drm_device *dev);
+ 
+ void ast_enable_vga(struct drm_device *dev)
+ {
+@@ -384,6 +385,9 @@ void ast_post_gpu(struct drm_device *dev)
+ 	else
+ 		ast_init_dram_reg(dev);
+ 
++	if (ast->chip == AST2400)
++		ast_init_output_control(dev);
++
+ 	ast_init_3rdtx(dev);
+ }
+ 
+@@ -1655,3 +1659,31 @@ static void ast_init_dram_2300(struct drm_device *dev)
+ 	} while ((reg & 0x40) == 0);
+ }
+ 
++static void ast_init_output_control(struct drm_device *dev)
++{
++	struct ast_private *ast = dev->dev_private;
++	const uint32_t scu_addr = 0x1e6e2000;
++	const uint32_t scu_key = 0x1688a8a8;
++	uint32_t val;
++
++	/* unlock write access to SCUs */
++	val = ast_mindwm(ast, scu_addr);
++	ast_moutdwm(ast, scu_addr, scu_key);
++
++	/* configure SCU2C with the appropriate video output mode */
++	val = ast_mindwm(ast, scu_addr | 0x2c);
++
++	switch (ast->tx_chip_type) {
++	case AST_TX_SIL164:
++	case AST_TX_DP501:
++		/* Enable DVO output */
++		val &= ~0x40000;
++		break;
++	default:
++		/* VGA only: enable DAC output */
++		val &= ~0x30000;
++		break;
++	}
++
++	ast_moutdwm(ast, scu_addr | 0x2c, val);
++}
+-- 
+2.7.0
+