[PATCH 2/4] lis302dl: tiny optimisation in __reg_set_bit_mask

NeilBrown neilb at suse.de
Mon Nov 2 02:32:45 CET 2009


Don't write out when there is nothing to change.

Signed-off-by: NeilBrown <neilb at suse.de>
---

 drivers/input/misc/lis302dl.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/drivers/input/misc/lis302dl.c b/drivers/input/misc/lis302dl.c
index 894f928..52eaccd 100644
--- a/drivers/input/misc/lis302dl.c
+++ b/drivers/input/misc/lis302dl.c
@@ -96,6 +96,8 @@ static void __reg_set_bit_mask(struct lis302dl_info *lis, u8 reg, u8 mask,
 	val &= mask;
 
 	tmp = __reg_read(lis, reg);
+	if ((tmp & mask) == val)
+		return;
 	tmp &= ~mask;
 	tmp |= val;
 	__reg_write(lis, reg, tmp);





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