From 789b3447c0c02fd0eec839f694446c0dd4eb3718 Mon Sep 17 00:00:00 2001 From: York Sun Date: Fri, 14 Nov 2014 17:17:50 -0800 Subject: [PATCH] driver/ddr/fsl: Add workaround for faulty SPD Some UDIMMs have faulty SPD with wrong mapping for DQ[36-39]. Using raw card spec in case this error is detected. Signed-off-by: York Sun --- drivers/ddr/fsl/ddr4_dimm_params.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/drivers/ddr/fsl/ddr4_dimm_params.c b/drivers/ddr/fsl/ddr4_dimm_params.c index 2418dca6ab..aaddc8fa08 100644 --- a/drivers/ddr/fsl/ddr4_dimm_params.c +++ b/drivers/ddr/fsl/ddr4_dimm_params.c @@ -126,6 +126,12 @@ ddr_compute_dimm_parameters(const generic_spd_eeprom_t *spd, { unsigned int retval; int i; + const u8 udimm_rc_e_dq[18] = { + 0x0c, 0x2c, 0x15, 0x35, 0x15, 0x35, 0x0b, 0x2c, 0x15, + 0x35, 0x0b, 0x35, 0x0b, 0x2c, 0x0b, 0x35, 0x15, 0x36 + }; + int spd_error = 0; + u8 *ptr; if (spd->mem_type) { if (spd->mem_type != SPD_MEMTYPE_DDR4) { @@ -179,6 +185,22 @@ ddr_compute_dimm_parameters(const generic_spd_eeprom_t *spd, /* Unbuffered DIMMs */ if (spd->mod_section.unbuffered.addr_mapping & 0x1) pdimm->mirrored_dimm = 1; + if ((spd->mod_section.unbuffered.mod_height & 0xe0) == 0 && + (spd->mod_section.unbuffered.ref_raw_card == 0x04)) { + /* Fix SPD error found on DIMMs with raw card E0 */ + for (i = 0; i < 18; i++) { + if (spd->mapping[i] == udimm_rc_e_dq[i]) + continue; + spd_error = 1; + debug("SPD byte %d: 0x%x, should be 0x%x\n", + 60 + i, spd->mapping[i], + udimm_rc_e_dq[i]); + ptr = (u8 *)&spd->mapping[i]; + *ptr = udimm_rc_e_dq[i]; + } + if (spd_error) + puts("SPD DQ mapping error fixed\n"); + } break; default: -- 2.30.2