linux-kernel - [PATCH 5.4 14/80] PM / QoS: Redefine FREQ_QOS_MAX_DEFAULT_VALUE to S32

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Date:   Thu, 19 Dec 2019 19:34:06 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Leonard Crestez <leonard.crestez@....com>,
        Matthias Kaehlcke <mka@...omium.org>,
        "Rafael J. Wysocki" <rafael.j.wysocki@...el.com>
Subject: [PATCH 5.4 14/80] PM / QoS: Redefine FREQ_QOS_MAX_DEFAULT_VALUE to S32_MAX

From: Leonard Crestez <leonard.crestez@....com>

commit c6a3aea93571a5393602256d8f74772bd64c8225 upstream.

QOS requests for DEFAULT_VALUE are supposed to be ignored but this is
not the case for FREQ_QOS_MAX. Adding one request for MAX_DEFAULT_VALUE
and one for a real value will cause freq_qos_read_value to unexpectedly
return MAX_DEFAULT_VALUE (-1).

This happens because freq_qos max value is aggregated with PM_QOS_MIN
but FREQ_QOS_MAX_DEFAULT_VALUE is (-1) so it's smaller than other
values.

Fix this by redefining FREQ_QOS_MAX_DEFAULT_VALUE to S32_MAX.

Looking at current users for freq_qos it seems that none of them create
requests for FREQ_QOS_MAX_DEFAULT_VALUE.

Fixes: 77751a466ebd ("PM: QoS: Introduce frequency QoS")
Signed-off-by: Leonard Crestez <leonard.crestez@....com>
Reported-by: Matthias Kaehlcke <mka@...omium.org>
Reviewed-by: Matthias Kaehlcke <mka@...omium.org>
Cc: 5.4+ <stable@...r.kernel.org> # 5.4+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 include/linux/pm_qos.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/include/linux/pm_qos.h
+++ b/include/linux/pm_qos.h
@@ -256,7 +256,7 @@ static inline s32 dev_pm_qos_raw_resume_
 #endif

 #define FREQ_QOS_MIN_DEFAULT_VALUE	0
-#define FREQ_QOS_MAX_DEFAULT_VALUE	(-1)
+#define FREQ_QOS_MAX_DEFAULT_VALUE	S32_MAX

 enum freq_qos_req_type {
 	FREQ_QOS_MIN = 1,