| Message ID | 1430558124-5783-1-git-send-email-javi.merino@arm.com (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Eduardo Valentin |
| Headers | show |
diff --git a/drivers/thermal/power_allocator.c b/drivers/thermal/power_allocator.c index 3ca7530deac6..4672250b329f 100644 --- a/drivers/thermal/power_allocator.c +++ b/drivers/thermal/power_allocator.c @@ -196,7 +196,8 @@ static void divvy_up_power(u32 *req_power, u32 *max_power, int num_actors, for (i = 0; i < num_actors; i++) { u64 req_range = req_power[i] * power_range; - granted_power[i] = div_u64(req_range, total_req_power); + granted_power[i] = DIV_ROUND_CLOSEST_ULL(req_range, + total_req_power); if (granted_power[i] > max_power[i]) { extra_power += granted_power[i] - max_power[i];
In situations where there is an uneven number of cooling devices, the division of power among them can lead to a milliwatt being dropped on the floor due to rounding errors. This doesn't sound like a lot, but some devices only grant the lowest cooling device state for their maximum power. So for instance, if the granted_power is the maximum power and all devices are getting their maximum power, one would get max_power - 1, making it choose cooling device state 1, instead of 0. Round the division to make the calculation more accurate. Cc: Zhang Rui <rui.zhang@intel.com> Cc: Eduardo Valentin <edubezval@gmail.com> Signed-off-by: Javi Merino <javi.merino@arm.com> --- Hi, This patch should apply on top of the linus branch in Eduardo's repository. drivers/thermal/power_allocator.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)