linux-kernel - [PATCH] thermal: gov_power_allocator: Fix incorrect calculation in divvy_up

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Message-Id: <20250219-fix-power-allocator-calc-v1-1-48b860291919@chromium.org>
Date: Wed, 19 Feb 2025 15:07:48 +0800
From: Yu-Che Cheng <giver@...omium.org>
To: Lukasz Luba <lukasz.luba@....com>, 
 "Rafael J. Wysocki" <rafael@...nel.org>, 
 Daniel Lezcano <daniel.lezcano@...aro.org>, Zhang Rui <rui.zhang@...el.com>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@...el.com>, 
 linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org, 
 Chen-Yu Tsai <wenst@...omium.org>, Yu-Che Cheng <giver@...omium.org>
Subject: [PATCH] thermal: gov_power_allocator: Fix incorrect calculation in
 divvy_up_power

divvy_up_power should use weighted_req_power instead of req_power to
calculate the granted_power. Otherwise, the granted_power may be
unexpected as the denominator total_req_power is weighted sum.

This is a mistake during the previous refactor.

Replace the req_power with weighted_req_power in divvy_up_power
calculation.

Fixes: 912e97c67cc3 ("thermal: gov_power_allocator: Move memory allocation out of throttle()")
Signed-off-by: Yu-Che Cheng <giver@...omium.org>
---
 drivers/thermal/gov_power_allocator.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/thermal/gov_power_allocator.c b/drivers/thermal/gov_power_allocator.c
index 3b644de3292e..3b626db55b2b 100644
--- a/drivers/thermal/gov_power_allocator.c
+++ b/drivers/thermal/gov_power_allocator.c
@@ -370,7 +370,7 @@ static void divvy_up_power(struct power_actor *power, int num_actors,

 	for (i = 0; i < num_actors; i++) {
 		struct power_actor *pa = &power[i];
-		u64 req_range = (u64)pa->req_power * power_range;
+		u64 req_range = (u64)pa->weighted_req_power * power_range;

 		pa->granted_power = DIV_ROUND_CLOSEST_ULL(req_range,
 							  total_req_power);

---
base-commit: 2408a807bfc3f738850ef5ad5e3fd59d66168996
change-id: 20250218-fix-power-allocator-calc-f00b4ab650ba

Best regards,
-- 
Yu-Che Cheng <giver@...omium.org>