diff options
| -rw-r--r-- | src/northbridge/intel/sandybridge/raminit_common.c | 39 |
1 files changed, 28 insertions, 11 deletions
diff --git a/src/northbridge/intel/sandybridge/raminit_common.c b/src/northbridge/intel/sandybridge/raminit_common.c index be0589dd8b..c6ff551fbf 100644 --- a/src/northbridge/intel/sandybridge/raminit_common.c +++ b/src/northbridge/intel/sandybridge/raminit_common.c @@ -2342,7 +2342,6 @@ static int try_cmd_stretch(ramctr_timing *ctrl, int channel, int cmd_stretch) int command_training(ramctr_timing *ctrl) { int channel; - int err; FOR_ALL_POPULATED_CHANNELS { fill_pattern5(ctrl, channel, 0); @@ -2350,17 +2349,35 @@ int command_training(ramctr_timing *ctrl) } FOR_ALL_POPULATED_CHANNELS { - /* try command rate 1T and 2T */ - err = try_cmd_stretch(ctrl, channel, 0); + int cmdrate, err; + + /* + * Dual DIMM per channel: + * Issue: While c320c discovery seems to succeed raminit + * will fail in write training. + * Workaround: Skip 1T in dual DIMM mode, that's only + * supported by a few DIMMs. + * TODO: How to detect "1T" DIMMs ? + * + * Single DIMM per channel: + * Try command rate 1T and 2T + */ + cmdrate = ((ctrl->rankmap[channel] & 0x5) == 0x5); + + for(; cmdrate < 2; cmdrate++) { + err = try_cmd_stretch(ctrl, channel, cmdrate << 1); + + if (!err) + break; + } + if (err) { - err = try_cmd_stretch(ctrl, channel, 2); - if (err) { - printk(BIOS_EMERG, "c320c discovery failed\n"); - return err; - } - printram("Using CMD rate 2T on channel %u\n", channel); - } else - printram("Using CMD rate 1T on channel %u\n", channel); + printk(BIOS_EMERG, "c320c discovery failed\n"); + return err; + } + + printram("Using CMD rate %uT on channel %u\n", + cmdrate + 1, channel); } FOR_ALL_POPULATED_CHANNELS |