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nb/amd/mct_ddr3: Fix x4 DIMM receiver enable training on Fam15h 

The existing Family 15h receiver enable training code stored
temporary delay values in the wrong variables, leading to
the requisite averaging of delays across nibbles not being
applied.  This in turn made x4 DIMMs less stable than they
should have been.

Store temporary nibble delay values in a dedicated array.

Change-Id: Ic5da898af7d689db4110211f89b886ccdbb5f78f
Signed-off-by: Timothy Pearson <tpearson@raptorengineeringinc.com>
Reviewed-on: https://review.coreboot.org/14541
Tested-by: build bot (Jenkins)
Tested-by: Raptor Engineering Automated Test Stand <noreply@raptorengineeringinc.com>
Reviewed-by: Martin Roth <martinroth@google.com>
This commit is contained in:
Timothy Pearson 2016-04-29 00:38:29 -05:00
parent efcee9fadd
commit 7f731f8d4f
1 changed files with 29 additions and 22 deletions
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29
src/northbridge/amd/amdmct/mct_ddr3/mctsrc.c
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@ -1194,6 +1194,7 @@ static void dqsTrainRcvrEn_SW_Fam15(struct MCTStatStruc *pMCTstat,
uint16_t initial_seed;
uint8_t train_both_nibbles;
uint16_t current_total_delay[MAX_BYTE_LANES];
uint16_t nibble0_current_total_delay[MAX_BYTE_LANES];
uint16_t dqs_ret_pass1_total_delay[MAX_BYTE_LANES];
uint16_t rank0_current_total_delay[MAX_BYTE_LANES];
uint16_t phase_recovery_delays[MAX_BYTE_LANES];
@ -1419,19 +1420,11 @@ static void dqsTrainRcvrEn_SW_Fam15(struct MCTStatStruc *pMCTstat,
for (lane = 0; lane < lane_count; lane++) {
current_total_delay[lane] = (phase_recovery_delays[lane] & 0x1f);
current_total_delay[lane] |= ((seed_gross[lane] + ((phase_recovery_delays[lane] >> 5) & 0x1f) - seed_pre_gross[lane] + 1) << 5);
if (nibble == 0) {
if (lane == 8)
pDCTstat->CH_D_BC_RCVRDLY[Channel][dimm] = current_total_delay[lane];
else
pDCTstat->CH_D_B_RCVRDLY[Channel][dimm][lane] = current_total_delay[lane];
} else {
if (nibble == 1) {
/* 2.10.5.8.2 (1)
* Average the trained values of both nibbles on x4 DIMMs
*/
if (lane == 8)
pDCTstat->CH_D_BC_RCVRDLY[Channel][dimm] = (pDCTstat->CH_D_BC_RCVRDLY[Channel][dimm] + current_total_delay[lane]) / 2;
else
pDCTstat->CH_D_B_RCVRDLY[Channel][dimm][lane] = (pDCTstat->CH_D_B_RCVRDLY[Channel][dimm][lane] + current_total_delay[lane]) / 2;
current_total_delay[lane] = (nibble0_current_total_delay[lane] + current_total_delay[lane]) / 2;
}
}
@ -1441,13 +1434,18 @@ static void dqsTrainRcvrEn_SW_Fam15(struct MCTStatStruc *pMCTstat,
Channel, dimm, nibble, lane, current_total_delay[lane], pDCTstat->CH_D_B_RCVRDLY[Channel][dimm][lane]);
#endif
write_dqs_receiver_enable_control_registers(current_total_delay, dev, Channel, dimm, index_reg);
if (nibble == 0) {
/* Back up the Nibble 0 delays for later use */
memcpy(nibble0_current_total_delay, current_total_delay, sizeof(current_total_delay));
}
}
if (_2Ranks) {
if (rank == 0) {
/* Back up the Rank 0 delays for later use */
memcpy(rank0_current_total_delay, current_total_delay, sizeof(current_total_delay));
}
if (rank == 1) {
/* 2.10.5.8.2 (8)
* Compute the average delay across both ranks and program the result into
@ -1462,6 +1460,15 @@ static void dqsTrainRcvrEn_SW_Fam15(struct MCTStatStruc *pMCTstat,
}
write_dqs_receiver_enable_control_registers(current_total_delay, dev, Channel, dimm, index_reg);
}
} else {
/* Save the current delay for later use by other routines */
for (lane = 0; lane < lane_count; lane++) {
if (lane == 8)
pDCTstat->CH_D_BC_RCVRDLY[Channel][dimm] = current_total_delay[lane];
else
pDCTstat->CH_D_B_RCVRDLY[Channel][dimm][lane] = current_total_delay[lane];
}
}
}
#if DQS_TRAIN_DEBUG > 0