Change in coreboot[master]: nb/intel/haswell: Ensure MCH has acked raminit

[Patrick Georgi (Code Review)]

Patrick Georgi has submitted this change. ( https://review.coreboot.org/c/coreboot/+/51940 )

Change subject: nb/intel/haswell: Ensure MCH has acked raminit
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nb/intel/haswell: Ensure MCH has acked raminit

Haswell MRC.bin can return zero even when raminit did not complete
successfully. When this happens, the memory controller will not have
acknowledged raminit: the mc_init_done_ack bit in the MC_INIT_STATE_G
register will be zero, and memory accesses will lock up the system.

To handle this situation more gracefully, check the mc_init_done_ack bit
after running MRC. If the bit is not set, log a fatal error and halt.

Tested on Asrock B85M Pro4:
- With badly-seated DIMMs, MRC raminit fails and coreboot dies.
- After reseating the DIMMs, the board still boots successfully.

Change-Id: I144bf827f65cd0be319c44bf3d407ddc116b129d
Signed-off-by: Angel Pons 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/51940
Tested-by: build bot (Jenkins) 
Reviewed-by: Arthur Heymans 
---
M src/northbridge/intel/haswell/raminit.c
1 file changed, 10 insertions(+), 0 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Arthur Heymans: Looks good to me, approved

diff --git a/src/northbridge/intel/haswell/raminit.c b/src/northbridge/intel/haswell/raminit.c
index 5da1129..ff2456b 100644
--- a/src/northbridge/intel/haswell/raminit.c
+++ b/src/northbridge/intel/haswell/raminit.c
@@ -169,6 +169,16 @@
    	(version >> 24) & 0xff, (version >> 16) & 0xff,
    	(version >>  8) & 0xff, (version >>  0) & 0xff);

+	/*
+	 * MRC may return zero even when raminit did not complete successfully.
+	 * Ensure the mc_init_done_ack bit is set before continuing. Otherwise,
+	 * attempting to access memory will lock up the system.
+	 */
+	if (!(MCHBAR32(MC_INIT_STATE_G) & (1 << 5))) {
+		printk(BIOS_EMERG, "Memory controller did not acknowledge raminit.\n");
+		die("MRC raminit failed\n");
+	}
+
    report_memory_config();
 }