File grub2-i386-pc-no-pageflipping.patch of Package grub2

In x86 Legacy BIOS mode, on some Lenovo machines, the grub menu is not
visible, although it demonstrably has been drawn (bsc#1245636).

A workaround to avoid this is to not use page flipping mode.

This patch enforces that no page flipping is used in the VBE framebuffer
backend for i386-pc.

--- a/grub-core/video/i386/pc/vbe.c
+++ b/grub-core/video/i386/pc/vbe.c
@@ -1137,7 +1137,8 @@ grub_video_vbe_setup (unsigned int width, unsigned int height,
 
 	page_size = framebuffer.mode_info.pitch * framebuffer.mode_info.height;
 
-	if (vram_size >= 2 * page_size)
+	/* avoid page flipping mode (bsc#1245636) */
+	if (0 && vram_size >= 2 * page_size)
 	  err = grub_video_fb_setup (mode_type, mode_mask,
 				     &framebuffer.mode_info,
 				     framebuffer.ptr,