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: 77751a466ebd ("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>

diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h
index ebf5ef17cc2ae3f45a1ff5379c387e2d0bc9a089..24a6263c99317931ebb7c77df3a170bad297780e 100644 (file)
--- a/include/linux/pm_qos.h
+++ b/include/linux/pm_qos.h
@@ -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,