From: Daniel Mack <daniel@caiaq.de>
Date: Fri, 24 Jul 2009 13:08:11 +0000 (+0200)
Subject: ds2760_battery: Fix integer overflow for time_to_empty_now
X-Git-Tag: v2.6.32-rc1~158^2~2
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=b0525b48;p=karo-tx-linux.git

ds2760_battery: Fix integer overflow for time_to_empty_now

On the device we're currently developing, battery sizes of ~2.8Ah and
current flow of ~600mA are typical.

With that values, the life_sec computation overflows due to the
multiplication by 3600.

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Cc: Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>
Cc: Matt Reimer <mreimer@vpop.net>
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
---

diff --git a/drivers/power/ds2760_battery.c b/drivers/power/ds2760_battery.c
index 1bb8498f14be..6f1dba5a519d 100644
--- a/drivers/power/ds2760_battery.c
+++ b/drivers/power/ds2760_battery.c
@@ -211,9 +211,9 @@ static int ds2760_battery_read_status(struct ds2760_device_info *di)
 	if (di->rem_capacity > 100)
 		di->rem_capacity = 100;
 
-	if (di->current_uA)
-		di->life_sec = -((di->accum_current_uAh - di->empty_uAh) *
-				 3600L) / di->current_uA;
+	if (di->current_uA >= 100L)
+		di->life_sec = -((di->accum_current_uAh - di->empty_uAh) * 36L)
+					/ (di->current_uA / 100L);
 	else
 		di->life_sec = 0;