From 4502df12aa0d097bb5382d369eade2f578ac015a Mon Sep 17 00:00:00 2001 From: Timothy Pearson Date: Thu, 27 Aug 2015 13:19:34 -0500 Subject: nb/amd/mct_ddr3: Fix odd rank data corruption The odd rank of each DIMM could experience data corruption due to incorrect DQS training. Fix the DQS training algorithm by executing the relevant portions of the training algorithm on the odd ranks. Change-Id: Ibc51f5052d5189e45b3d9aa98ca8febbfe13f178 Signed-off-by: Timothy Pearson Reviewed-on: https://review.coreboot.org/12058 Tested-by: build bot (Jenkins) Reviewed-by: Martin Roth Reviewed-by: Paul Menzel Reviewed-by: Patrick Georgi --- src/northbridge/amd/amdmct/mct_ddr3/mctdqs_d.c | 25 +++++++++++++++++-------- 1 file changed, 17 insertions(+), 8 deletions(-) (limited to 'src/northbridge/amd/amdmct') diff --git a/src/northbridge/amd/amdmct/mct_ddr3/mctdqs_d.c b/src/northbridge/amd/amdmct/mct_ddr3/mctdqs_d.c index 06597e23bb..9362a60961 100644 --- a/src/northbridge/amd/amdmct/mct_ddr3/mctdqs_d.c +++ b/src/northbridge/amd/amdmct/mct_ddr3/mctdqs_d.c @@ -1320,9 +1320,9 @@ static uint8_t TrainDQSRdWrPos_D_Fam15(struct MCTStatStruc *pMCTstat, Receiver = receiver_start; /* There are four receiver pairs, loosely associated with chipselects. - * This is essentially looping over each DIMM. + * This is essentially looping over each rank within each DIMM. */ - for (; Receiver < receiver_end; Receiver += 2) { + for (; Receiver < receiver_end; Receiver++) { dimm = (Receiver >> 1); if ((Receiver & 0x1) == 0) { /* Even rank of DIMM */ @@ -1336,18 +1336,27 @@ static uint8_t TrainDQSRdWrPos_D_Fam15(struct MCTStatStruc *pMCTstat, continue; } +#if DQS_TRAIN_DEBUG > 0 + printk(BIOS_DEBUG, "TrainDQSRdWrPos: Training DQS read/write position for receiver %d (DIMM %d)\n", Receiver, dimm); +#endif + /* Initialize variables */ for (lane = lane_start; lane < lane_end; lane++) { passing_dqs_delay_found[lane] = 0; } - memset(dqs_results_array, 0, sizeof(dqs_results_array)); + if ((Receiver & 0x1) == 0) { + /* Even rank of DIMM */ + memset(dqs_results_array, 0, sizeof(dqs_results_array)); + + /* Read initial read / write DQS delays */ + read_dqs_write_timing_control_registers(initial_write_dqs_delay, dev, dct, dimm, index_reg); + read_dqs_read_data_timing_registers(initial_read_dqs_delay, dev, dct, dimm, index_reg); - /* Read initial read / write DQS delays */ - read_dqs_write_timing_control_registers(initial_write_dqs_delay, dev, dct, dimm, index_reg); - read_dqs_read_data_timing_registers(initial_read_dqs_delay, dev, dct, dimm, index_reg); + /* Read current settings of other (previously trained) lanes */ + read_dqs_write_data_timing_registers(initial_write_data_timing, dev, dct, dimm, index_reg); + } - /* Read current settings of other (previously trained) lanes */ - read_dqs_write_data_timing_registers(initial_write_data_timing, dev, dct, dimm, index_reg); + /* Initialize iterators */ memcpy(current_write_data_delay, initial_write_data_timing, sizeof(current_write_data_delay)); for (lane = lane_start; lane < lane_end; lane++) { -- cgit v1.2.3