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| author | Matti Vaittinen <mazziesaccount@gmail.com> | 2024-02-12 14:20:09 +0300 |
|---|---|---|
| committer | Sasha Levin <sashal@kernel.org> | 2024-03-27 01:17:29 +0300 |
| commit | f8ca7ac74370e151c20199d0a06618a03301f146 (patch) | |
| tree | 4484c883596042cfe64426e081d1eed77dccf7e2 | |
| parent | 257b26293786443db541ee5b4044719dcdc2ba1b (diff) | |
| download | linux-f8ca7ac74370e151c20199d0a06618a03301f146.tar.xz | |
iio: gts-helper: Fix division loop
[ Upstream commit bb76cc45dcdfcd962a5994b8fe19ab74fc6c3c3a ]
The loop based 64bit division may run for a long time when dividend is a
lot bigger than the divider. Replace the division loop by the
div64_u64() which implementation may be significantly faster.
Tested-by: Subhajit Ghosh <subhajit.ghosh@tweaklogic.com>
Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Fixes: 38416c28e168 ("iio: light: Add gain-time-scale helpers")
Link: https://lore.kernel.org/r/Zcn-6e-0-nh2WcfU@drtxq0yyyyyyyyyyyyyby-3.rev.dnainternet.fi
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/iio/industrialio-gts-helper.c | 15 |
1 files changed, 1 insertions, 14 deletions
diff --git a/drivers/iio/industrialio-gts-helper.c b/drivers/iio/industrialio-gts-helper.c index 7653261d2dc2..b51eb6cb766f 100644 --- a/drivers/iio/industrialio-gts-helper.c +++ b/drivers/iio/industrialio-gts-helper.c @@ -34,24 +34,11 @@ static int iio_gts_get_gain(const u64 max, const u64 scale) { u64 full = max; - int tmp = 1; if (scale > full || !scale) return -EINVAL; - if (U64_MAX - full < scale) { - /* Risk of overflow */ - if (full - scale < scale) - return 1; - - full -= scale; - tmp++; - } - - while (full > scale * (u64)tmp) - tmp++; - - return tmp; + return div64_u64(full, scale); } /** |