This function is a treasure trove of ad-hoc iterative implementations of mathematical functions. Replace all of those with their non-iterative counterpart.
Signed-off-by: Marek Vasut marex@denx.de --- drivers/ddr/altera/sequencer.c | 31 +++++++++++++++---------------- 1 file changed, 15 insertions(+), 16 deletions(-)
diff --git a/drivers/ddr/altera/sequencer.c b/drivers/ddr/altera/sequencer.c index 4c4b36c..eb246cc 100644 --- a/drivers/ddr/altera/sequencer.c +++ b/drivers/ddr/altera/sequencer.c @@ -1492,28 +1492,27 @@ static int sdr_find_window_centre(const u32 grp, const u32 work_bgn, debug_cond(DLEVEL == 2, "work_bgn=%d work_end=%d work_mid=%d\n", work_bgn, work_end, work_mid); /* Get the middle delay to be less than a VFIFO delay */ - for (p = 0; p <= IO_DQS_EN_PHASE_MAX; - p++, tmp_delay += IO_DELAY_PER_OPA_TAP) - ; + tmp_delay = (IO_DQS_EN_PHASE_MAX + 1) * IO_DELAY_PER_OPA_TAP;
debug_cond(DLEVEL == 2, "vfifo ptap delay %d\n", tmp_delay); - while (work_mid > tmp_delay) - work_mid -= tmp_delay; + work_mid %= tmp_delay; debug_cond(DLEVEL == 2, "new work_mid %d\n", work_mid);
- tmp_delay = 0; - for (p = 0; p <= IO_DQS_EN_PHASE_MAX && tmp_delay < work_mid; - p++, tmp_delay += IO_DELAY_PER_OPA_TAP) - ; - tmp_delay -= IO_DELAY_PER_OPA_TAP; - debug_cond(DLEVEL == 2, "new p %d, tmp_delay=%d\n", p - 1, tmp_delay); + tmp_delay = rounddown(work_mid, IO_DELAY_PER_OPA_TAP); + if (tmp_delay > IO_DQS_EN_PHASE_MAX * IO_DELAY_PER_OPA_TAP) + tmp_delay = IO_DQS_EN_PHASE_MAX * IO_DELAY_PER_OPA_TAP; + p = tmp_delay / IO_DELAY_PER_OPA_TAP; + + debug_cond(DLEVEL == 2, "new p %d, tmp_delay=%d\n", p, tmp_delay); + + d = DIV_ROUND_UP(work_mid - tmp_delay, IO_DELAY_PER_DQS_EN_DCHAIN_TAP); + if (d > IO_DQS_EN_DELAY_MAX) + d = IO_DQS_EN_DELAY_MAX; + tmp_delay += d * IO_DELAY_PER_DQS_EN_DCHAIN_TAP;
- for (d = 0; d <= IO_DQS_EN_DELAY_MAX && tmp_delay < work_mid; - d++, tmp_delay += IO_DELAY_PER_DQS_EN_DCHAIN_TAP) - ; debug_cond(DLEVEL == 2, "new d %d, tmp_delay=%d\n", d, tmp_delay);
- scc_mgr_set_dqs_en_phase_all_ranks(grp, p - 1); + scc_mgr_set_dqs_en_phase_all_ranks(grp, p); scc_mgr_set_dqs_en_delay_all_ranks(grp, d);
/* @@ -1540,7 +1539,7 @@ static int sdr_find_window_centre(const u32 grp, const u32 work_bgn, } else { debug_cond(DLEVEL == 2, "%s:%d center: found: vfifo=%u ptap=%u dtap=%u\n", - __func__, __LINE__, v, p - 1, d); + __func__, __LINE__, v, p, d); return 1; } }