From 5f55836ab41671e005038255fdd60482718d2ca2 Mon Sep 17 00:00:00 2001 From: Clive Lin Date: Mon, 31 Jul 2023 14:03:54 +0800 Subject: [PATCH] PM: QoS: Add check to make sure CPU latency is non-negative CPU latency should never be negative, which will be incorrectly high when converted to unsigned data type. Commit 8d36694245f2 ("PM: QoS: Add check to make sure CPU freq is non-negative") makes sure CPU frequency is non-negative to fix incorrect behavior in freqency QoS. Add an analogous check to make sure CPU latency is non-negative so as to prevent this problem from happening in CPU latency QoS. Signed-off-by: Clive Lin [ rjw: Changelog edits ] Signed-off-by: Rafael J. Wysocki --- kernel/power/qos.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/kernel/power/qos.c b/kernel/power/qos.c index 782d3b41c1f3..4244b069442e 100644 --- a/kernel/power/qos.c +++ b/kernel/power/qos.c @@ -220,6 +220,11 @@ static struct pm_qos_constraints cpu_latency_constraints = { .type = PM_QOS_MIN, }; +static inline bool cpu_latency_qos_value_invalid(s32 value) +{ + return value < 0 && value != PM_QOS_DEFAULT_VALUE; +} + /** * cpu_latency_qos_limit - Return current system-wide CPU latency QoS limit. */ @@ -263,7 +268,7 @@ static void cpu_latency_qos_apply(struct pm_qos_request *req, */ void cpu_latency_qos_add_request(struct pm_qos_request *req, s32 value) { - if (!req) + if (!req || cpu_latency_qos_value_invalid(value)) return; if (cpu_latency_qos_request_active(req)) { @@ -289,7 +294,7 @@ EXPORT_SYMBOL_GPL(cpu_latency_qos_add_request); */ void cpu_latency_qos_update_request(struct pm_qos_request *req, s32 new_value) { - if (!req) + if (!req || cpu_latency_qos_value_invalid(new_value)) return; if (!cpu_latency_qos_request_active(req)) {