nb/x4x/raminit.c: Remove ME locking code
This code ought not to run if ME is disabled. It also prohibits
writing to some GMCH regs like GGC bit1.
Intel ® 4 Series Chipset Family datasheet refers to this as
"ME stolen Memory lock" without actually describing this
functionality.
Change-Id: Iaa8646e535e13c44c010ccd434a5af954cf7dfbc
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/18513
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
diff --git a/src/northbridge/intel/x4x/raminit_ddr2.c b/src/northbridge/intel/x4x/raminit_ddr2.c
index eca7189..35caaa6 100644
--- a/src/northbridge/intel/x4x/raminit_ddr2.c
+++ b/src/northbridge/intel/x4x/raminit_ddr2.c
@@ -2106,15 +2106,19 @@
printk(BIOS_DEBUG, "Done power settings\n");
// ME related
- if (RANK_IS_POPULATED(s->dimms, 0, 0)
- || RANK_IS_POPULATED(s->dimms, 1, 0)) {
- MCHBAR8(0xa2f) = MCHBAR8(0xa2f) | (1 << 0);
+ /*
+ * FIXME: This locks some registers like bit1 of GGC
+ * and is only needed in case of ME being used.
+ */
+ if (ME_UMA_SIZEMB != 0) {
+ if (RANK_IS_POPULATED(s->dimms, 0, 0)
+ || RANK_IS_POPULATED(s->dimms, 1, 0))
+ MCHBAR8(0xa2f) = MCHBAR8(0xa2f) | (1 << 0);
+ if (RANK_IS_POPULATED(s->dimms, 0, 1)
+ || RANK_IS_POPULATED(s->dimms, 1, 1))
+ MCHBAR8(0xa2f) = MCHBAR8(0xa2f) | (1 << 1);
+ MCHBAR32(0xa30) = MCHBAR32(0xa30) | (1 << 26);
}
- if (RANK_IS_POPULATED(s->dimms, 0, 1)
- || RANK_IS_POPULATED(s->dimms, 1, 1)) {
- MCHBAR8(0xa2f) = MCHBAR8(0xa2f) | (1 << 1);
- }
- MCHBAR32(0xa30) = MCHBAR32(0xa30) | (1 << 26);
printk(BIOS_DEBUG, "Done ddr2\n");
}