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From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Linux PM <linux-pm@vger.kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
	Amit Kucheria <amit.kucheria@linaro.org>
Subject: [PATCH 04/28] PM: QoS: Clean up pm_qos_update_target() and pm_qos_update_flags()
Date: Tue, 11 Feb 2020 23:58:33 +0100	[thread overview]
Message-ID: <1746259.hJgS1hQAGi@kreacher> (raw)
In-Reply-To: <1654227.8mz0SueHsU@kreacher>

From: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>

Clean up the pm_qos_update_target() function:
 * Update its kerneldoc comment.
 * Drop the redundant ret local variable from it.
 * Reorder definitions of local variables in it.
 * Update a comment in it.

Also update the kerneldoc comment of pm_qos_update_flags() (e.g.
notifiers are not called by it any more) and add one emtpy line
to its body (for more visual clarity).

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 kernel/power/qos.c | 56 ++++++++++++++++++++++++++++--------------------------
 1 file changed, 29 insertions(+), 27 deletions(-)

diff --git a/kernel/power/qos.c b/kernel/power/qos.c
index a6be7faa1974..6a36809d6160 100644
--- a/kernel/power/qos.c
+++ b/kernel/power/qos.c
@@ -129,24 +129,30 @@ static inline void pm_qos_set_value(struct pm_qos_constraints *c, s32 value)
 }
 
 /**
- * pm_qos_update_target - manages the constraints list and calls the notifiers
- *  if needed
- * @c: constraints data struct
- * @node: request to add to the list, to update or to remove
- * @action: action to take on the constraints list
- * @value: value of the request to add or update
+ * pm_qos_update_target - Update a list of PM QoS constraint requests.
+ * @c: List of PM QoS requests.
+ * @node: Target list entry.
+ * @action: Action to carry out (add, update or remove).
+ * @value: New request value for the target list entry.
  *
- * This function returns 1 if the aggregated constraint value has changed, 0
- *  otherwise.
+ * Update the given list of PM QoS constraint requests, @c, by carrying an
+ * @action involving the @node list entry and @value on it.
+ *
+ * The recognized values of @action are PM_QOS_ADD_REQ (store @value in @node
+ * and add it to the list), PM_QOS_UPDATE_REQ (remove @node from the list, store
+ * @value in it and add it to the list again), and PM_QOS_REMOVE_REQ (remove
+ * @node from the list, ignore @value).
+ *
+ * Return: 1 if the aggregate constraint value has changed, 0  otherwise.
  */
 int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node,
 			 enum pm_qos_req_action action, int value)
 {
-	unsigned long flags;
 	int prev_value, curr_value, new_value;
-	int ret;
+	unsigned long flags;
 
 	spin_lock_irqsave(&pm_qos_lock, flags);
+
 	prev_value = pm_qos_get_value(c);
 	if (value == PM_QOS_DEFAULT_VALUE)
 		new_value = c->default_value;
@@ -159,9 +165,8 @@ int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node,
 		break;
 	case PM_QOS_UPDATE_REQ:
 		/*
-		 * to change the list, we atomically remove, reinit
-		 * with new value and add, then see if the extremal
-		 * changed
+		 * To change the list, atomically remove, reinit with new value
+		 * and add, then see if the aggregate has changed.
 		 */
 		plist_del(node, &c->list);
 		/* fall through */
@@ -180,16 +185,14 @@ int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node,
 	spin_unlock_irqrestore(&pm_qos_lock, flags);
 
 	trace_pm_qos_update_target(action, prev_value, curr_value);
-	if (prev_value != curr_value) {
-		ret = 1;
-		if (c->notifiers)
-			blocking_notifier_call_chain(c->notifiers,
-						     (unsigned long)curr_value,
-						     NULL);
-	} else {
-		ret = 0;
-	}
-	return ret;
+
+	if (prev_value == curr_value)
+		return 0;
+
+	if (c->notifiers)
+		blocking_notifier_call_chain(c->notifiers, curr_value, NULL);
+
+	return 1;
 }
 
 /**
@@ -211,14 +214,12 @@ static void pm_qos_flags_remove_req(struct pm_qos_flags *pqf,
 
 /**
  * pm_qos_update_flags - Update a set of PM QoS flags.
- * @pqf: Set of flags to update.
+ * @pqf: Set of PM QoS flags to update.
  * @req: Request to add to the set, to modify, or to remove from the set.
  * @action: Action to take on the set.
  * @val: Value of the request to add or modify.
  *
- * Update the given set of PM QoS flags and call notifiers if the aggregate
- * value has changed.  Returns 1 if the aggregate constraint value has changed,
- * 0 otherwise.
+ * Return: 1 if the aggregate constraint value has changed, 0 otherwise.
  */
 bool pm_qos_update_flags(struct pm_qos_flags *pqf,
 			 struct pm_qos_flags_request *req,
@@ -254,6 +255,7 @@ bool pm_qos_update_flags(struct pm_qos_flags *pqf,
 	spin_unlock_irqrestore(&pm_qos_lock, irqflags);
 
 	trace_pm_qos_update_flags(action, prev_value, curr_value);
+
 	return prev_value != curr_value;
 }
 
-- 
2.16.4






  parent reply	other threads:[~2020-02-11 23:39 UTC|newest]

Thread overview: 83+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-11 22:51 [PATCH 00/28] PM: QoS: Get rid of unuseful code and rework CPU latency QoS interface Rafael J. Wysocki
2020-02-11 22:52 ` [PATCH 01/28] PM: QoS: Drop debugfs interface Rafael J. Wysocki
2020-02-11 22:58 ` [PATCH 02/28] PM: QoS: Drop pm_qos_update_request_timeout() Rafael J. Wysocki
2020-02-11 22:58 ` [PATCH 03/28] PM: QoS: Drop the PM_QOS_SUM QoS type Rafael J. Wysocki
2020-02-11 22:58 ` Rafael J. Wysocki [this message]
2020-02-11 22:58 ` [PATCH 05/28] PM: QoS: Clean up pm_qos_read_value() and pm_qos_get/set_value() Rafael J. Wysocki
2020-02-11 22:59 ` [PATCH 06/28] PM: QoS: Drop iterations over global QoS classes Rafael J. Wysocki
2020-02-11 23:00 ` [PATCH 07/28] PM: QoS: Clean up misc device file operations Rafael J. Wysocki
2020-02-11 23:01 ` [PATCH 08/28] PM: QoS: Redefine struct pm_qos_request and drop struct pm_qos_object Rafael J. Wysocki
2020-02-11 23:02 ` [PATCH 09/28] PM: QoS: Drop PM_QOS_CPU_DMA_LATENCY notifier chain Rafael J. Wysocki
2020-02-11 23:04 ` [PATCH 10/28] PM: QoS: Rename things related to the CPU latency QoS Rafael J. Wysocki
2020-02-12 10:34   ` Rafael J. Wysocki
2020-02-12 19:13   ` Greg Kroah-Hartman
2020-02-11 23:06 ` [PATCH 11/28] PM: QoS: Simplify definitions of CPU latency QoS trace events Rafael J. Wysocki
2020-02-11 23:07 ` [PATCH 12/28] PM: QoS: Adjust pm_qos_request() signature and reorder pm_qos.h Rafael J. Wysocki
2020-02-11 23:07 ` [PATCH 13/28] PM: QoS: Add CPU latency QoS API wrappers Rafael J. Wysocki
2020-02-11 23:08 ` [PATCH 14/28] cpuidle: Call cpu_latency_qos_limit() instead of pm_qos_request() Rafael J. Wysocki
2020-02-11 23:10 ` [PATCH 15/28] x86: platform: iosf_mbi: Call cpu_latency_qos_*() instead of pm_qos_*() Rafael J. Wysocki
2020-02-12 10:14   ` Andy Shevchenko
2020-02-11 23:12 ` [PATCH 16/28] drm: i915: " Rafael J. Wysocki
2020-02-11 23:12   ` [Intel-gfx] " Rafael J. Wysocki
2020-02-12 10:32   ` Rafael J. Wysocki
2020-02-12 10:32     ` [Intel-gfx] " Rafael J. Wysocki
2020-02-14  7:42   ` Jani Nikula
2020-02-14  7:42     ` [Intel-gfx] " Jani Nikula
2020-02-11 23:13 ` [PATCH 17/28] drivers: hsi: " Rafael J. Wysocki
2020-02-13 21:06   ` Sebastian Reichel
2020-02-11 23:17 ` [PATCH 18/28] drivers: media: " Rafael J. Wysocki
2020-02-12  5:37   ` Mauro Carvalho Chehab
2020-02-11 23:21 ` [PATCH 19/28] drivers: mmc: " Rafael J. Wysocki
2020-02-11 23:24 ` [PATCH 20/28] drivers: net: " Rafael J. Wysocki
2020-02-11 23:48   ` Jeff Kirsher
2020-02-12  5:49   ` Kalle Valo
2020-02-11 23:26 ` [PATCH 21/28] drivers: spi: " Rafael J. Wysocki
2020-02-11 23:26   ` Rafael J. Wysocki
2020-02-11 23:27 ` [PATCH 22/28] drivers: tty: " Rafael J. Wysocki
2020-02-12 10:35   ` Rafael J. Wysocki
2020-02-12 19:13   ` Greg Kroah-Hartman
2020-02-11 23:28 ` [PATCH 23/28] drivers: usb: " Rafael J. Wysocki
2020-02-12 18:38   ` Greg KH
2020-02-18  8:03     ` Peter Chen
2020-02-18  8:08       ` Greg KH
2020-02-18  8:11         ` Peter Chen
2020-02-19  1:09   ` Peter Chen
2020-02-11 23:34 ` [PATCH 24/28] sound: " Rafael J. Wysocki
2020-02-11 23:34   ` [alsa-devel] " Rafael J. Wysocki
2020-02-12 10:08   ` Mark Brown
2020-02-12 10:08     ` [alsa-devel] " Mark Brown
2020-02-12 10:16     ` Rafael J. Wysocki
2020-02-12 10:16       ` [alsa-devel] " Rafael J. Wysocki
2020-02-12 10:21       ` Takashi Iwai
2020-02-12 10:21         ` [alsa-devel] " Takashi Iwai
2020-02-12 10:18   ` Mark Brown
2020-02-12 10:18     ` [alsa-devel] " Mark Brown
2020-02-11 23:35 ` [PATCH 25/28] PM: QoS: Drop PM_QOS_CPU_DMA_LATENCY and rename related functions Rafael J. Wysocki
2020-02-11 23:35 ` [PATCH 26/28] PM: QoS: Update file information comments Rafael J. Wysocki
2020-02-11 23:36 ` [PATCH 27/28] Documentation: PM: QoS: Update to reflect previous code changes Rafael J. Wysocki
2020-02-11 23:37 ` [PATCH 28/28] PM: QoS: Make CPU latency QoS depend on CONFIG_CPU_IDLE Rafael J. Wysocki
2020-02-12  8:37 ` [PATCH 00/28] PM: QoS: Get rid of unuseful code and rework CPU latency QoS interface Ulf Hansson
2020-02-12  9:17   ` Rafael J. Wysocki
2020-02-12  9:39 ` Rafael J. Wysocki
2020-02-12 23:32 ` Francisco Jerez
2020-02-13  0:16   ` Rafael J. Wysocki
2020-02-13  0:37     ` Rafael J. Wysocki
2020-02-13  8:10       ` Francisco Jerez
2020-02-13 11:38         ` Rafael J. Wysocki
2020-02-21 22:10           ` Francisco Jerez
2020-02-24  0:29             ` Rafael J. Wysocki
2020-02-24 21:06               ` Francisco Jerez
2020-02-13  8:07     ` Francisco Jerez
2020-02-13 11:34       ` Rafael J. Wysocki
2020-02-13 16:35         ` Rafael J. Wysocki
2020-02-14  0:15           ` Francisco Jerez
2020-02-14 10:42             ` Rafael J. Wysocki
2020-02-14 20:32               ` Francisco Jerez
2020-02-24 10:39                 ` Rafael J. Wysocki
2020-02-24 21:16                   ` Francisco Jerez
2020-02-14  0:14         ` Francisco Jerez
2020-02-13  7:10 ` Amit Kucheria
2020-02-13 10:17   ` Rafael J. Wysocki
2020-02-13 10:22     ` Rafael J. Wysocki
2020-02-13 10:49     ` Amit Kucheria
2020-02-13 11:36       ` Rafael J. Wysocki

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