Linux-libre 4.4-gnupck-4.4-gnu

1 files changed, 23 insertions, 1 deletions

diff --git a/drivers/video/fbdev/efifb.c b/drivers/video/fbdev/efifb.c
index 4bfff349b..95d293b74 100644
--- a/drivers/video/fbdev/efifb.c
+++ b/drivers/video/fbdev/efifb.c
@@ -114,6 +114,20 @@ static int efifb_setup(char *options)
 	return 0;
 }
 
+static inline bool fb_base_is_valid(void)
+{
+	if (screen_info.lfb_base)
+		return true;
+
+	if (!(screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE))
+		return false;
+
+	if (screen_info.ext_lfb_base)
+		return true;
+
+	return false;
+}
+
 static int efifb_probe(struct platform_device *dev)
 {
 	struct fb_info *info;
@@ -141,7 +155,7 @@ static int efifb_probe(struct platform_device *dev)
 		screen_info.lfb_depth = 32;
 	if (!screen_info.pages)
 		screen_info.pages = 1;
-	if (!screen_info.lfb_base) {
+	if (!fb_base_is_valid()) {
 		printk(KERN_DEBUG "efifb: invalid framebuffer address\n");
 		return -ENODEV;
 	}
@@ -160,6 +174,14 @@ static int efifb_probe(struct platform_device *dev)
 	}
 
 	efifb_fix.smem_start = screen_info.lfb_base;
+
+	if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE) {
+		u64 ext_lfb_base;
+
+		ext_lfb_base = (u64)(unsigned long)screen_info.ext_lfb_base << 32;
+		efifb_fix.smem_start |= ext_lfb_base;
+	}
+
 	efifb_defined.bits_per_pixel = screen_info.lfb_depth;
 	efifb_defined.xres = screen_info.lfb_width;
 	efifb_defined.yres = screen_info.lfb_height;