colibri_t20: clear LVDS/HDMI framebuffers

Instead of copying the boot loader frame buffer which currently neither
displays anything worth preserving nor even what it has in the right
resolution make sure both LVDS as well as HDMI frame buffers get
cleared during initialisation to avoid displaying random garbled stuff.

1 files changed, 16 insertions, 8 deletions

diff --git a/arch/arm/mach-tegra/board-colibri_t20-panel.c b/arch/arm/mach-tegra/board-colibri_t20-panel.c
index 6089e0512711..006f668659cb 100644
--- a/arch/arm/mach-tegra/board-colibri_t20-panel.c
+++ b/arch/arm/mach-tegra/board-colibri_t20-panel.c
@@ -521,6 +521,7 @@ int __init colibri_t20_panel_init(void)
 {
 	int err;
 	struct resource __maybe_unused *res;
+	void __iomem *to_io;
 
 	/* enable hdmi hotplug gpio for hotplug detection */
 	gpio_request(colibri_t20_hdmi_hpd, "hdmi_hpd");
@@ -559,14 +560,21 @@ int __init colibri_t20_panel_init(void)
 	res->end = tegra_fb2_start + tegra_fb2_size - 1;
 #endif /* CONFIG_TEGRA_GRHOST && CONFIG_TEGRA_DC */
 
-	/* Copy the bootloader fb to the fb. */
-	tegra_move_framebuffer(tegra_fb_start, tegra_bootloader_fb_start,
-		min(tegra_fb_size, tegra_bootloader_fb_size));
-
-	/* Copy the bootloader fb to the fb2. */
-	tegra_move_framebuffer(tegra_fb2_start, tegra_bootloader_fb_start,
-		min(tegra_fb2_size, tegra_bootloader_fb_size));
-
+	/* Make sure LVDS framebuffer is cleared. */
+	to_io = ioremap(tegra_fb_start, tegra_fb_size);
+	if (to_io) {
+		memset(to_io, 0, tegra_fb_size);
+		iounmap(to_io);
+	} else pr_err("%s: Failed to map LVDS framebuffer\n", __func__);
+
+	/* Make sure HDMI framebuffer is cleared.
+	   Note: this seems to fix a tegradc.1 initialisation race in case of
+	   framebuffer console as well. */
+	to_io = ioremap(tegra_fb2_start, tegra_fb2_size);
+	if (to_io) {
+		memset(to_io, 0, tegra_fb2_size);
+		iounmap(to_io);
+	} else pr_err("%s: Failed to map HDMI framebuffer\n", __func__);
 
 #if defined(CONFIG_TEGRA_GRHOST) && defined(CONFIG_TEGRA_DC)
 	if (!err)