From 26a64351234093fbeea6e776be8829eae012ce7f Mon Sep 17 00:00:00 2001 From: Nico Huber Date: Tue, 14 May 2013 11:43:03 +0200 Subject: intel/gm45: Refactor DDR3 read training Split some code in individual functions. It's the refactoring part of a bigger change, following... Change-Id: Ied551a011eaf22f6f8f6db0044de3634134f0b37 Signed-off-by: Nico Huber Reviewed-on: http://review.coreboot.org/3253 Tested-by: build bot (Jenkins) Reviewed-by: Stefan Reinauer --- .../intel/gm45/raminit_read_write_training.c | 74 ++++++++++++++-------- 1 file changed, 46 insertions(+), 28 deletions(-) (limited to 'src/northbridge/intel') diff --git a/src/northbridge/intel/gm45/raminit_read_write_training.c b/src/northbridge/intel/gm45/raminit_read_write_training.c index 8c8e66a807..6936d0788f 100644 --- a/src/northbridge/intel/gm45/raminit_read_write_training.c +++ b/src/northbridge/intel/gm45/raminit_read_write_training.c @@ -99,50 +99,68 @@ static int read_training_test(const int channel, const int lane, } return 1; } -static void read_training_per_lane(const int channel, const int lane, - const address_bunch_t *const addresses) +static void read_training_find_lower(const int channel, const int lane, + const address_bunch_t *const addresses, + read_timing_t *const lower) { - read_timing_t lower, upper; - - MCHBAR32(CxRDTy_MCHBAR(channel, lane)) |= 3 << 25; - - /* Search lower bound. */ - lower.t = 0; - lower.p = 0; - program_read_timing(channel, lane, &lower); /* Coarse search for good t. */ + program_read_timing(channel, lane, lower); while (!read_training_test(channel, lane, addresses)) { - ++lower.t; - program_read_timing(channel, lane, &lower); + ++lower->t; + program_read_timing(channel, lane, lower); } + /* Step back, then fine search for good p. */ - if (lower.t > 0) { - --lower.t; - program_read_timing(channel, lane, &lower); + if (lower->t > 0) { + --lower->t; + program_read_timing(channel, lane, lower); while (!read_training_test(channel, lane, addresses)) { - ++lower.p; - program_read_timing(channel, lane, &lower); + ++lower->p; + program_read_timing(channel, lane, lower); } } - - /* Search upper bound. */ - upper.t = lower.t + 1; - upper.p = lower.p; - program_read_timing(channel, lane, &upper); +} +static void read_training_find_upper(const int channel, const int lane, + const address_bunch_t *const addresses, + read_timing_t *const upper) +{ + program_read_timing(channel, lane, upper); if (!read_training_test(channel, lane, addresses)) die("Read training failed: limits too narrow.\n"); /* Coarse search for bad t. */ do { - ++upper.t; - program_read_timing(channel, lane, &upper); + ++upper->t; + program_read_timing(channel, lane, upper); } while (read_training_test(channel, lane, addresses)); /* Fine search for bad p. */ - --upper.t; - program_read_timing(channel, lane, &upper); + --upper->t; + program_read_timing(channel, lane, upper); while (read_training_test(channel, lane, addresses)) { - ++upper.p; - program_read_timing(channel, lane, &upper); + ++upper->p; + program_read_timing(channel, lane, upper); } +} +static void read_training_per_lane(const int channel, const int lane, + const address_bunch_t *const addresses) +{ + read_timing_t lower, upper; + + MCHBAR32(CxRDTy_MCHBAR(channel, lane)) |= 3 << 25; + + /*** Search lower bound. ***/ + + /* Start at zero. */ + lower.t = 0; + lower.p = 0; + read_training_find_lower(channel, lane, addresses, &lower); + + /*** Search upper bound. ***/ + + /* Start at lower + 1t. */ + upper.t = lower.t + 1; + upper.p = lower.p; + + read_training_find_upper(channel, lane, addresses, &upper); /* Calculate and program mean value. */ lower.p += lower.t << READ_TIMING_P_SHIFT; -- cgit v1.2.3