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authoranish kumar <anish198519851985@gmail.com>2012-08-29 23:05:10 +0400
committerMyungJoo Ham <myungjoo.ham@samsung.com>2012-10-22 06:28:10 +0400
commit28c0ada62d39eaafef03d88a4e6f4c5bcb6e1b6c (patch)
tree6f4f01eab4ad9c1e59265362a3077a50449cba60 /drivers/extcon
parent0cf6ad8a18f7f7bdbb81975188d9e0656ef277dd (diff)
downloadlinux-28c0ada62d39eaafef03d88a4e6f4c5bcb6e1b6c.tar.xz
extcon: optimising the check_mutually_exclusive function
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>
Diffstat (limited to 'drivers/extcon')
-rw-r--r--drivers/extcon/extcon-class.c16
1 files changed, 6 insertions, 10 deletions
diff --git a/drivers/extcon/extcon-class.c b/drivers/extcon/extcon-class.c
index 1e1a3f17a782..1ce76a8d777b 100644
--- a/drivers/extcon/extcon-class.c
+++ b/drivers/extcon/extcon-class.c
@@ -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;