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Subject[RFC 5/6] Input: mt: document adjust_dual()
Date
adjust_dual() is really cryptic right now.
To try to understand what the function does, replace the variable names
with the following:
f -> first
p -> cur
s -> stop
c -> center

Also add a partial doc that needs to be filled by someone who knows
what the function is actually doing.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
---
drivers/input/input-mt.c | 44 ++++++++++++++++++++++++++++----------------
1 file changed, 28 insertions(+), 16 deletions(-)

diff --git a/drivers/input/input-mt.c b/drivers/input/input-mt.c
index e43c33c..c7b3752 100644
--- a/drivers/input/input-mt.c
+++ b/drivers/input/input-mt.c
@@ -293,33 +293,45 @@ void input_mt_sync_frame(struct input_dev *dev)
}
EXPORT_SYMBOL(input_mt_sync_frame);

+/**
+ * adjust_dual() -
+ * @begin
+ * @step
+ * @end
+ * @eq
+ *
+ * FIXME -- can someone tell what this function does???
+ */
static int adjust_dual(int *begin, int step, int *end, int eq)
{
- int f, *p, s, c;
+ int first, *cur, stop, center;

if (begin == end)
return 0;

- f = *begin;
- p = begin + step;
- s = p == end ? f + 1 : *p;
+ first = *begin;
+ cur = begin + step;
+ stop = cur == end ? first + 1 : *cur;

- for (; p != end; p += step)
- if (*p < f)
- s = f, f = *p;
- else if (*p < s)
- s = *p;
+ for (; cur != end; cur += step) {
+ if (*cur < first) {
+ stop = first;
+ first = *cur;
+ } else if (*cur < stop) {
+ stop = *cur;
+ }
+ }

- c = (f + s + 1) / 2;
- if (c == 0 || (c > 0 && !eq))
+ center = (first + stop + 1) / 2;
+ if (center == 0 || (center > 0 && !eq))
return 0;
- if (s < 0)
- c *= 2;
+ if (stop < 0)
+ center *= 2;

- for (p = begin; p != end; p += step)
- *p -= c;
+ for (cur = begin; cur != end; cur += step)
+ *cur -= center;

- return (c < s && s <= 0) || (f >= 0 && f < c);
+ return (center < stop && stop <= 0) || (first >= 0 && first < center);
}

/**
--
2.1.0


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