nb/intel/*/gma.c: Skip NGI when VGA decode is not enabled
Writes to VGA MEM and IO by NGI are invalid if the IGD is not decoding
them.
Change-Id: I4b9329d14105eb563a0d4aea6ef75ff11febf6df
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/27984
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
diff --git a/src/northbridge/intel/haswell/gma.c b/src/northbridge/intel/haswell/gma.c
index 8ffdce8..8f60da4 100644
--- a/src/northbridge/intel/haswell/gma.c
+++ b/src/northbridge/intel/haswell/gma.c
@@ -468,10 +468,17 @@
/* Pre panel init */
gma_setup_panel(dev);
+ int vga_disable = (pci_read_config16(dev, GGC) & 2) >> 1;
+
if (IS_ENABLED(CONFIG_MAINBOARD_USE_LIBGFXINIT)) {
- printk(BIOS_SPEW, "NATIVE graphics, run native enable\n");
- gma_gfxinit(&lightup_ok);
- gfx_set_init_done(1);
+ if (vga_disable) {
+ printk(BIOS_INFO,
+ "IGD is not decoding legacy VGA MEM and IO: skipping NATIVE graphic init\n");
+ } else {
+ printk(BIOS_SPEW, "NATIVE graphics, run native enable\n");
+ gma_gfxinit(&lightup_ok);
+ gfx_set_init_done(1);
+ }
}
if (! lightup_ok) {