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extcon: optimising the check_mutually_exclusive function

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Rather than re-inventing the wheel we can use the hamming function
to calculate the number of bits set to check for violation of
exclusivity.

Signed-off-by: anish kumar <anish198519851985@gmail.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
This commit is contained in:
anish kumar 2012-08-30 00:35:10 +05:30 committed by MyungJoo Ham
parent 0cf6ad8a18
commit 28c0ada62d
1 changed files with 5 additions and 9 deletions
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14
drivers/extcon/extcon-class.c
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@ -89,17 +89,13 @@ static int check_mutually_exclusive(struct extcon_dev *edev, u32 new_state)
return 0;
for (i = 0; edev->mutually_exclusive[i]; i++) {
int count = 0, j;
int weight;
u32 correspondants = new_state & edev->mutually_exclusive[i];
u32 exp = 1;
for (j = 0; j < 32; j++) {
if (exp & correspondants)
count++;
if (count > 1)
return i + 1;
exp <<= 1;
}
/* calculate the total number of bits set */
weight = hweight32(correspondants);
if (weight > 1)
return i + 1;
}
return 0;