From 44241628bb207ec211bebd156aaf69470d90c209 Mon Sep 17 00:00:00 2001 From: Andrea Arcangeli Date: Thu, 1 Oct 2015 15:37:16 -0700 Subject: thermal: avoid division by zero in power allocator During boot I get a div by zero Oops regression starting in v4.3-rc3. Signed-off-by: Andrea Arcangeli Reviewed-by: Javi Merino Cc: Zhang Rui Cc: Eduardo Valentin Cc: Daniel Kurtz Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/thermal/power_allocator.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'drivers') diff --git a/drivers/thermal/power_allocator.c b/drivers/thermal/power_allocator.c index 7ff96270c933..e570ff084add 100644 --- a/drivers/thermal/power_allocator.c +++ b/drivers/thermal/power_allocator.c @@ -144,6 +144,16 @@ static void estimate_pid_constants(struct thermal_zone_device *tz, switch_on_temp = 0; temperature_threshold = control_temp - switch_on_temp; + /* + * estimate_pid_constants() tries to find appropriate default + * values for thermal zones that don't provide them. If a + * system integrator has configured a thermal zone with two + * passive trip points at the same temperature, that person + * hasn't put any effort to set up the thermal zone properly + * so just give up. + */ + if (!temperature_threshold) + return; if (!tz->tzp->k_po || force) tz->tzp->k_po = int_to_frac(sustainable_power) / -- cgit v1.2.3