Messages in this thread Patch in this message | | | From | Andrea Arcangeli <> | Subject | [PATCH] thermal: avoid division by zero in power allocator | Date | Mon, 28 Sep 2015 23:28:34 +0200 |
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During boot I get a div by zero Oops regression starting in v4.3-rc3.
Reviewed-by: Javi Merino <javi.merino@arm.com> Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> --- drivers/thermal/power_allocator.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/drivers/thermal/power_allocator.c b/drivers/thermal/power_allocator.c index 7ff9627..e570ff0 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) /
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