power: supply: cpcap-battery: Fix division by zero

[ Upstream commit dbe7208c6c4aec083571f2ec742870a0d0edbea3 ]

If called fast enough so samples do not increment, we can get
division by zero in kernel:

__div0
cpcap_battery_cc_raw_div
cpcap_battery_get_property
power_supply_get_property.part.1
power_supply_get_property
power_supply_show_property
power_supply_uevent

Fixes: 874b2adbed12 ("power: supply: cpcap-battery: Add a battery driver")
Signed-off-by: Tony Lindgren <tony@atomide.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/power/supply/cpcap-battery.c b/drivers/power/supply/cpcap-battery.c
index 98ba078..3bae023 100644 (file)
--- a/drivers/power/supply/cpcap-battery.c
+++ b/drivers/power/supply/cpcap-battery.c
@@ -221,6 +221,9 @@ static int cpcap_battery_cc_raw_div(struct cpcap_battery_ddata *ddata,
        int avg_current;
        u32 cc_lsb;
 
+       if (!divider)
+               return 0;
+
        sample &= 0xffffff;             /* 24-bits, unsigned */
        offset &= 0x7ff;                /* 10-bits, signed */