2 files changed, 23 insertions, 0 deletions

diff --git a/drivers/video/sm501fb.c b/drivers/video/sm501fb.c
index d97edd7a6e41..1be95a68d696 100644
--- a/drivers/video/sm501fb.c
+++ b/drivers/video/sm501fb.c
@@ -777,6 +777,11 @@ static int sm501fb_set_par_pnl(struct fb_info *info)
         writel(control, fbi->regs + SM501_DC_PANEL_CONTROL);
         sm501fb_sync_regs(fbi);
 
+        /* ensure the panel interface is not tristated at this point */
+
+        sm501_modify_reg(fbi->dev->parent, SM501_SYSTEM_CONTROL,
+                         0, SM501_SYSCTRL_PANEL_TRISTATE);
+
         /* power the panel up */
         sm501fb_panel_power(fbi, 1);
         return 0;
diff --git a/include/linux/sm501-regs.h b/include/linux/sm501-regs.h
index 014e73b31fc0..df7620dd8f31 100644
--- a/include/linux/sm501-regs.h
+++ b/include/linux/sm501-regs.h
@@ -15,6 +15,24 @@
 
 /* config 1 */
 #define SM501_SYSTEM_CONTROL            (0x000000)
+
+#define SM501_SYSCTRL_PANEL_TRISTATE    (1<<0)
+#define SM501_SYSCTRL_MEM_TRISTATE      (1<<1)
+#define SM501_SYSCTRL_CRT_TRISTATE      (1<<2)
+
+#define SM501_SYSCTRL_PCI_SLAVE_BURST_MASK (3<<4)
+#define SM501_SYSCTRL_PCI_SLAVE_BURST_1 (0<<4)
+#define SM501_SYSCTRL_PCI_SLAVE_BURST_2 (1<<4)
+#define SM501_SYSCTRL_PCI_SLAVE_BURST_4 (2<<4)
+#define SM501_SYSCTRL_PCI_SLAVE_BURST_8 (3<<4)
+
+#define SM501_SYSCTRL_PCI_CLOCK_RUN_EN  (1<<6)
+#define SM501_SYSCTRL_PCI_RETRY_DISABLE (1<<7)
+#define SM501_SYSCTRL_PCI_SUBSYS_LOCK   (1<<11)
+#define SM501_SYSCTRL_PCI_BURST_READ_EN (1<<15)
+
+/* miscellaneous control */
+
 #define SM501_MISC_CONTROL              (0x000004)
 
 #define SM501_MISC_BUS_SH               (0x0)