From 6462cbb2c20bae0cf309a3eb4ce70adff573e75a Mon Sep 17 00:00:00 2001 From: Angel Pons Date: Tue, 30 Mar 2021 11:01:25 +0200 Subject: [PATCH] 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 --- src/northbridge/intel/haswell/raminit.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/src/northbridge/intel/haswell/raminit.c b/src/northbridge/intel/haswell/raminit.c index 5da11299ba..ff2456bef1 100644 --- a/src/northbridge/intel/haswell/raminit.c +++ b/src/northbridge/intel/haswell/raminit.c @@ -169,6 +169,16 @@ static void sdram_initialize(struct pei_data *pei_data) (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(); }