linux-kernel - [PATCH] thermal: gov_power_allocator: Granted power set to max when nobody request power

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Message-ID: <20241021121138.422-1-zhengshaobo1@xiaomi.com>
Date: Mon, 21 Oct 2024 20:11:38 +0800
From: ZhengShaobo <zhengshaobo1@...omi.com>
To: Lukasz Luba <lukasz.luba@....com>, "Rafael J . Wysocki"
	<rafael@...nel.org>, Daniel Lezcano <daniel.lezcano@...aro.org>, Zhang Rui
	<rui.zhang@...el.com>, <linux-pm@...r.kernel.org>,
	<linux-kernel@...r.kernel.org>
CC: zhuzhangwei <chuci@...omi.com>, dingchongchong
	<dingchongchong@...omi.com>, chendejun <chendejun@...omi.com>, zhengshaobo1
	<zhengshaobo1@...omi.com>
Subject: [PATCH] thermal: gov_power_allocator: Granted power set to max when nobody request power

From: zhengshaobo1 <zhengshaobo1@...omi.com>

When total_req_power is 0, divvy_up_power() will set granted_power to 0,
and cdev will be limited to the lowest performance. If our polling delay
is set to 200ms, it means that cdev cannot perform better within 200ms
even if cdev has a sudden load. This will affect the performance of cdev
and is not as expected.

For this reason, if nobody requests power, then set the granted power to
the max_power.

Signed-off-by: zhengshaobo1 <zhengshaobo1@...omi.com>
---
 drivers/thermal/gov_power_allocator.c | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/drivers/thermal/gov_power_allocator.c b/drivers/thermal/gov_power_allocator.c
index 1b2345a697c5..4301516c0938 100644
--- a/drivers/thermal/gov_power_allocator.c
+++ b/drivers/thermal/gov_power_allocator.c
@@ -356,11 +356,19 @@ static void divvy_up_power(struct power_actor *power, int num_actors,
 	u32 extra_power = 0;
 	int i;
 
-	/*
-	 * Prevent division by 0 if none of the actors request power.
-	 */
-	if (!total_req_power)
-		total_req_power = 1;
+	if (!total_req_power) {
+		/*
+		 * Nobody requested anything, just give everybody
+		 * the maximum power
+		 */
+		for (i = 0; i < num_actors; i++) {
+			struct power_actor *pa = &power[i];
+
+			pa->granted_power = pa->max_power;
+		}
+
+		return;
+	}
 
 	for (i = 0; i < num_actors; i++) {
 		struct power_actor *pa = &power[i];
-- 
2.43.0