Commit c6a3aea9 authored Nov 26, 2019 by Leonard Crestez Committed by Rafael J. Wysocki Nov 29, 2019

PM / QoS: Redefine FREQ_QOS_MAX_DEFAULT_VALUE to S32_MAX



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: 77751a46 ("PM: QoS: Introduce frequency QoS")
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Reported-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Cc: 5.4+ <stable@vger.kernel.org> # 5.4+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

parent 6e9f8796

include/linux/pm_qos.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -256,7 +256,7 @@ static inline s32 dev_pm_qos_raw_resume_latency(struct device *dev)
		#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,

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