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| author | Angel Pons <th3fanbus@gmail.com> | 2020-11-11 18:40:06 +0100 |
|---|---|---|
| committer | Patrick Georgi <pgeorgi@google.com> | 2020-11-16 12:07:20 +0000 |
| commit | bf13ef0738a7898b4877491a0aaa95aabf4700b5 (patch) | |
| tree | 819c9ad675802db22fac7dd50fe602f988b54503 /src | |
| parent | 3b9d3e92c0dbdec5b6ee466fe4a80b2eef417328 (diff) | |
| download | coreboot-bf13ef0738a7898b4877491a0aaa95aabf4700b5.tar.xz | |
nb/intel/sandybridge: Clarify some parts of raminit
Put names and expand comments for some parts of the code.
Change-Id: If1f83bf113ef08469768a9e4dd13819f76633f18
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/47489
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Diffstat (limited to 'src')
| -rw-r--r-- | src/northbridge/intel/sandybridge/raminit_common.c | 31 |
1 files changed, 18 insertions, 13 deletions
diff --git a/src/northbridge/intel/sandybridge/raminit_common.c b/src/northbridge/intel/sandybridge/raminit_common.c index 57c28fc9f4..20c048f7f2 100644 --- a/src/northbridge/intel/sandybridge/raminit_common.c +++ b/src/northbridge/intel/sandybridge/raminit_common.c @@ -2321,17 +2321,17 @@ static int get_timB_high_adjust(u64 val) { int i; - /* good */ + /* DQS is good enough */ if (val == 0xffffffffffffffffLL) return 0; if (val >= 0xf000000000000000LL) { - /* needs negative adjustment */ + /* DQS is late, needs negative adjustment */ for (i = 0; i < 8; i++) if (val << (8 * (7 - i) + 4)) return -i; } else { - /* needs positive adjustment */ + /* DQS is early, needs positive adjustment */ for (i = 0; i < 8; i++) if (val >> (8 * (7 - i) + 4)) return i; @@ -2339,7 +2339,7 @@ static int get_timB_high_adjust(u64 val) return 8; } -static void adjust_high_timB(ramctr_timing *ctrl) +static void train_write_flyby(ramctr_timing *ctrl) { int channel, slotrank, lane, old; MCHBAR32(GDCRTRAININGMOD) = 0x200; @@ -2715,7 +2715,7 @@ int write_training(ramctr_timing *ctrl) program_timings(ctrl, channel); /* measure and adjust timB timings */ - adjust_high_timB(ctrl); + train_write_flyby(ctrl); FOR_ALL_POPULATED_CHANNELS program_timings(ctrl, channel); @@ -2726,7 +2726,7 @@ int write_training(ramctr_timing *ctrl) return 0; } -static int test_320c(ramctr_timing *ctrl, int channel, int slotrank) +static int test_command_training(ramctr_timing *ctrl, int channel, int slotrank) { struct ram_rank_timings saved_rt = ctrl->timings[channel][slotrank]; int timC_delta; @@ -3006,14 +3006,18 @@ static void reprogram_320c(ramctr_timing *ctrl) toggle_io_reset(); } +#define CT_MIN_PI -127 +#define CT_MAX_PI 128 +#define CT_PI_LENGTH (CT_MAX_PI - CT_MIN_PI + 1) + #define MIN_C320C_LEN 13 static int try_cmd_stretch(ramctr_timing *ctrl, int channel, int cmd_stretch) { struct ram_rank_timings saved_timings[NUM_CHANNELS][NUM_SLOTRANKS]; int slotrank; - int c320c; - int stat[NUM_SLOTRANKS][256]; + int command_pi; + int stat[NUM_SLOTRANKS][CT_PI_LENGTH]; int delta = 0; printram("Trying cmd_stretch %d on channel %d\n", cmd_stretch, channel); @@ -3042,20 +3046,21 @@ static int try_cmd_stretch(ramctr_timing *ctrl, int channel, int cmd_stretch) ctrl->timings[channel][slotrank].roundtrip_latency -= delta; } - for (c320c = -127; c320c <= 127; c320c++) { + for (command_pi = CT_MIN_PI; command_pi < CT_MAX_PI; command_pi++) { FOR_ALL_POPULATED_RANKS { - ctrl->timings[channel][slotrank].pi_coding = c320c; + ctrl->timings[channel][slotrank].pi_coding = command_pi; } program_timings(ctrl, channel); reprogram_320c(ctrl); FOR_ALL_POPULATED_RANKS { - stat[slotrank][c320c + 127] = test_320c(ctrl, channel, slotrank); + stat[slotrank][command_pi - CT_MIN_PI] = + test_command_training(ctrl, channel, slotrank); } } FOR_ALL_POPULATED_RANKS { - struct run rn = get_longest_zero_run(stat[slotrank], 255); + struct run rn = get_longest_zero_run(stat[slotrank], CT_PI_LENGTH - 1); - ctrl->timings[channel][slotrank].pi_coding = rn.middle - 127; + ctrl->timings[channel][slotrank].pi_coding = rn.middle + CT_MIN_PI; printram("cmd_stretch: %d, %d: 0x%02x-0x%02x-0x%02x\n", channel, slotrank, rn.start, rn.middle, rn.end); |