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[v4,02/14] HID: hid-input: round return value of hidinput_calc_abs_res

Message ID 1352908766-4492-3-git-send-email-benjamin.tissoires@gmail.com (mailing list archive)
State New, archived
Delegated to: Jiri Kosina
Headers show

Commit Message

Benjamin Tissoires Nov. 14, 2012, 3:59 p.m. UTC 
hidinput_calc_abs_res should return the closest int in the division
instead of the floor.
On a device with a logical_max of 3008 and a physical_max of 255mm,
previous implementation gave a resolution of 11 instead of 12.
With 11, user-space computes a physical size of 273.5mm and the
round_closest results gives 250.6mm.
The old implementation introduced an error of 2cm in this example.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
---
 drivers/hid/hid-input.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox

Patch

diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
index f5b1d57..67044f3 100644
--- a/drivers/hid/hid-input.c
+++ b/drivers/hid/hid-input.c
@@ -287,7 +287,7 @@  __s32 hidinput_calc_abs_res(const struct hid_field *field, __u16 code)
 	}
 
 	/* Calculate resolution */
-	return logical_extents / physical_extents;
+	return DIV_ROUND_CLOSEST(logical_extents, physical_extents);
 }
 EXPORT_SYMBOL_GPL(hidinput_calc_abs_res);