video: tegra20: dc: clean framebuffer memory block

Fill the framebuffer memory with zeros to avoid visual glitches.

Signed-off-by: Jonas Schwöbel <jonasschwoebel@yahoo.de>
Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
diff --git a/drivers/video/tegra20/tegra-dc.c b/drivers/video/tegra20/tegra-dc.c
index 07d6ac9..10ad21e 100644
--- a/drivers/video/tegra20/tegra-dc.c
+++ b/drivers/video/tegra20/tegra-dc.c
@@ -4,6 +4,7 @@
  */
 
 #include <backlight.h>
+#include <cpu_func.h>
 #include <dm.h>
 #include <fdtdec.h>
 #include <log.h>
@@ -381,6 +382,10 @@
 		priv->scdiv = dc_plat->scdiv;
 	}
 
+	/* Clean the framebuffer area */
+	memset((u8 *)plat->base, 0, plat->size);
+	flush_dcache_all();
+
 	if (tegra_display_probe(priv, (void *)plat->base)) {
 		debug("%s: Failed to probe display driver\n", __func__);
 		return -1;