diff mbox series

[1/4] leds: Change led_trigger_blink[_oneshot]() delay parameters to pass-by-value

Message ID 20230412215855.593541-2-hdegoede@redhat.com
State Superseded
Headers show
Series Fix oops about sleeping in led_trigger_blink() | expand

Commit Message

Hans de Goede April 12, 2023, 9:58 p.m. UTC 
led_blink_set[_oneshot]()'s delay_on and delay_off function parameters
are pass by reference, so that hw-blink implementations can report
back the actual achieved delays when the values have been rounded
to something the hw supports.

This is really only interesting for the sysfs API / the timer trigger.
Other triggers don't really care about this and none of the callers of
led_trigger_blink[_oneshot]() do anything with the returned delay values.

Change the led_trigger_blink[_oneshot]() delay parameters to pass-by-value,
there are 2 reasons for this:

1. led_cdev->blink_set() may sleep, while led_trigger_blink() may not.
So on hw where led_cdev->blink_set() sleeps the call needs to be deferred
to a workqueue, in which case the actual achieved delays are unknown
(this is a preparation patch for the deferring).

2. Since the callers don't care about the actual achieved delays, allowing
callers to directly pass a value leads to simpler code for most callers.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/leds/led-triggers.c              | 16 ++++++++--------
 drivers/leds/trigger/ledtrig-disk.c      |  9 +++------
 drivers/leds/trigger/ledtrig-mtd.c       |  8 ++------
 drivers/net/arcnet/arcnet.c              |  8 ++------
 drivers/power/supply/power_supply_leds.c |  5 +----
 drivers/usb/common/led.c                 |  4 +---
 include/linux/leds.h                     | 16 ++++++++--------
 net/mac80211/led.c                       |  2 +-
 net/mac80211/led.h                       |  8 ++------
 net/netfilter/xt_LED.c                   |  3 +--
 10 files changed, 29 insertions(+), 50 deletions(-)

Comments

Lee Jones May 10, 2023, 11:57 a.m. UTC | #1 
On Wed, 12 Apr 2023, Hans de Goede wrote:

> led_blink_set[_oneshot]()'s delay_on and delay_off function parameters
> are pass by reference, so that hw-blink implementations can report
> back the actual achieved delays when the values have been rounded
> to something the hw supports.
> 
> This is really only interesting for the sysfs API / the timer trigger.
> Other triggers don't really care about this and none of the callers of
> led_trigger_blink[_oneshot]() do anything with the returned delay values.
> 
> Change the led_trigger_blink[_oneshot]() delay parameters to pass-by-value,
> there are 2 reasons for this:
> 
> 1. led_cdev->blink_set() may sleep, while led_trigger_blink() may not.
> So on hw where led_cdev->blink_set() sleeps the call needs to be deferred
> to a workqueue, in which case the actual achieved delays are unknown
> (this is a preparation patch for the deferring).
> 
> 2. Since the callers don't care about the actual achieved delays, allowing
> callers to directly pass a value leads to simpler code for most callers.
> 
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
>  drivers/leds/led-triggers.c              | 16 ++++++++--------
>  drivers/leds/trigger/ledtrig-disk.c      |  9 +++------
>  drivers/leds/trigger/ledtrig-mtd.c       |  8 ++------
>  drivers/net/arcnet/arcnet.c              |  8 ++------
>  drivers/power/supply/power_supply_leds.c |  5 +----
>  drivers/usb/common/led.c                 |  4 +---
>  include/linux/leds.h                     | 16 ++++++++--------
>  net/mac80211/led.c                       |  2 +-
>  net/mac80211/led.h                       |  8 ++------
>  net/netfilter/xt_LED.c                   |  3 +--
>  10 files changed, 29 insertions(+), 50 deletions(-)

Just came to apply this and realised that you have touched other
subsystems without Cc'ing the appropriate maintainers.

Please can you [RESEND] this set and include them please?
Hans de Goede May 10, 2023, 3:32 p.m. UTC | #2 
Hi,

On 5/10/23 13:57, Lee Jones wrote:
> On Wed, 12 Apr 2023, Hans de Goede wrote:
> 
>> led_blink_set[_oneshot]()'s delay_on and delay_off function parameters
>> are pass by reference, so that hw-blink implementations can report
>> back the actual achieved delays when the values have been rounded
>> to something the hw supports.
>>
>> This is really only interesting for the sysfs API / the timer trigger.
>> Other triggers don't really care about this and none of the callers of
>> led_trigger_blink[_oneshot]() do anything with the returned delay values.
>>
>> Change the led_trigger_blink[_oneshot]() delay parameters to pass-by-value,
>> there are 2 reasons for this:
>>
>> 1. led_cdev->blink_set() may sleep, while led_trigger_blink() may not.
>> So on hw where led_cdev->blink_set() sleeps the call needs to be deferred
>> to a workqueue, in which case the actual achieved delays are unknown
>> (this is a preparation patch for the deferring).
>>
>> 2. Since the callers don't care about the actual achieved delays, allowing
>> callers to directly pass a value leads to simpler code for most callers.
>>
>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>> ---
>>  drivers/leds/led-triggers.c              | 16 ++++++++--------
>>  drivers/leds/trigger/ledtrig-disk.c      |  9 +++------
>>  drivers/leds/trigger/ledtrig-mtd.c       |  8 ++------
>>  drivers/net/arcnet/arcnet.c              |  8 ++------
>>  drivers/power/supply/power_supply_leds.c |  5 +----
>>  drivers/usb/common/led.c                 |  4 +---
>>  include/linux/leds.h                     | 16 ++++++++--------
>>  net/mac80211/led.c                       |  2 +-
>>  net/mac80211/led.h                       |  8 ++------
>>  net/netfilter/xt_LED.c                   |  3 +--
>>  10 files changed, 29 insertions(+), 50 deletions(-)
> 
> Just came to apply this and realised that you have touched other
> subsystems without Cc'ing the appropriate maintainers.

Good point, sorry about that.

> Please can you [RESEND] this set and include them please?

Ack, I'm rebasing them on 6.4-rc1, checking no new
users of led_trigger_blink() / led_trigger_blink_oneshot()
(which this set changes the prototype of) have shown up
and then I'll do a resend.

(if I have to make any changes other then the plain rebase
I'll make it a version 2 set instead.)

Regards,

Hans
diff mbox series

Patch

diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c
index 072491d3e17b..e06361165e9b 100644
--- a/drivers/leds/led-triggers.c
+++ b/drivers/leds/led-triggers.c
@@ -393,8 +393,8 @@  void led_trigger_event(struct led_trigger *trig,
 EXPORT_SYMBOL_GPL(led_trigger_event);
 
 static void led_trigger_blink_setup(struct led_trigger *trig,
-			     unsigned long *delay_on,
-			     unsigned long *delay_off,
+			     unsigned long delay_on,
+			     unsigned long delay_off,
 			     int oneshot,
 			     int invert)
 {
@@ -406,25 +406,25 @@  static void led_trigger_blink_setup(struct led_trigger *trig,
 	rcu_read_lock();
 	list_for_each_entry_rcu(led_cdev, &trig->led_cdevs, trig_list) {
 		if (oneshot)
-			led_blink_set_oneshot(led_cdev, delay_on, delay_off,
+			led_blink_set_oneshot(led_cdev, &delay_on, &delay_off,
 					      invert);
 		else
-			led_blink_set(led_cdev, delay_on, delay_off);
+			led_blink_set(led_cdev, &delay_on, &delay_off);
 	}
 	rcu_read_unlock();
 }
 
 void led_trigger_blink(struct led_trigger *trig,
-		       unsigned long *delay_on,
-		       unsigned long *delay_off)
+		       unsigned long delay_on,
+		       unsigned long delay_off)
 {
 	led_trigger_blink_setup(trig, delay_on, delay_off, 0, 0);
 }
 EXPORT_SYMBOL_GPL(led_trigger_blink);
 
 void led_trigger_blink_oneshot(struct led_trigger *trig,
-			       unsigned long *delay_on,
-			       unsigned long *delay_off,
+			       unsigned long delay_on,
+			       unsigned long delay_off,
 			       int invert)
 {
 	led_trigger_blink_setup(trig, delay_on, delay_off, 1, invert);
diff --git a/drivers/leds/trigger/ledtrig-disk.c b/drivers/leds/trigger/ledtrig-disk.c
index 0b7dfbd04273..e9b87ee944f2 100644
--- a/drivers/leds/trigger/ledtrig-disk.c
+++ b/drivers/leds/trigger/ledtrig-disk.c
@@ -19,16 +19,13 @@  DEFINE_LED_TRIGGER(ledtrig_disk_write);
 
 void ledtrig_disk_activity(bool write)
 {
-	unsigned long blink_delay = BLINK_DELAY;
-
-	led_trigger_blink_oneshot(ledtrig_disk,
-				  &blink_delay, &blink_delay, 0);
+	led_trigger_blink_oneshot(ledtrig_disk, BLINK_DELAY, BLINK_DELAY, 0);
 	if (write)
 		led_trigger_blink_oneshot(ledtrig_disk_write,
-					  &blink_delay, &blink_delay, 0);
+					  BLINK_DELAY, BLINK_DELAY, 0);
 	else
 		led_trigger_blink_oneshot(ledtrig_disk_read,
-					  &blink_delay, &blink_delay, 0);
+					  BLINK_DELAY, BLINK_DELAY, 0);
 }
 EXPORT_SYMBOL(ledtrig_disk_activity);
 
diff --git a/drivers/leds/trigger/ledtrig-mtd.c b/drivers/leds/trigger/ledtrig-mtd.c
index 8fa763c2269b..bbe6876a249d 100644
--- a/drivers/leds/trigger/ledtrig-mtd.c
+++ b/drivers/leds/trigger/ledtrig-mtd.c
@@ -22,12 +22,8 @@  DEFINE_LED_TRIGGER(ledtrig_nand);
 
 void ledtrig_mtd_activity(void)
 {
-	unsigned long blink_delay = BLINK_DELAY;
-
-	led_trigger_blink_oneshot(ledtrig_mtd,
-				  &blink_delay, &blink_delay, 0);
-	led_trigger_blink_oneshot(ledtrig_nand,
-				  &blink_delay, &blink_delay, 0);
+	led_trigger_blink_oneshot(ledtrig_mtd, BLINK_DELAY, BLINK_DELAY, 0);
+	led_trigger_blink_oneshot(ledtrig_nand, BLINK_DELAY, BLINK_DELAY, 0);
 }
 EXPORT_SYMBOL(ledtrig_mtd_activity);
 
diff --git a/drivers/net/arcnet/arcnet.c b/drivers/net/arcnet/arcnet.c
index 1bad1866ae46..99265667538c 100644
--- a/drivers/net/arcnet/arcnet.c
+++ b/drivers/net/arcnet/arcnet.c
@@ -196,13 +196,10 @@  static void arcnet_dump_packet(struct net_device *dev, int bufnum,
 void arcnet_led_event(struct net_device *dev, enum arcnet_led_event event)
 {
 	struct arcnet_local *lp = netdev_priv(dev);
-	unsigned long led_delay = 350;
-	unsigned long tx_delay = 50;
 
 	switch (event) {
 	case ARCNET_LED_EVENT_RECON:
-		led_trigger_blink_oneshot(lp->recon_led_trig,
-					  &led_delay, &led_delay, 0);
+		led_trigger_blink_oneshot(lp->recon_led_trig, 350, 350, 0);
 		break;
 	case ARCNET_LED_EVENT_OPEN:
 		led_trigger_event(lp->tx_led_trig, LED_OFF);
@@ -213,8 +210,7 @@  void arcnet_led_event(struct net_device *dev, enum arcnet_led_event event)
 		led_trigger_event(lp->recon_led_trig, LED_OFF);
 		break;
 	case ARCNET_LED_EVENT_TX:
-		led_trigger_blink_oneshot(lp->tx_led_trig,
-					  &tx_delay, &tx_delay, 0);
+		led_trigger_blink_oneshot(lp->tx_led_trig, 50, 50, 0);
 		break;
 	}
 }
diff --git a/drivers/power/supply/power_supply_leds.c b/drivers/power/supply/power_supply_leds.c
index 702bf83f6e6d..e2f554e4e4e6 100644
--- a/drivers/power/supply/power_supply_leds.c
+++ b/drivers/power/supply/power_supply_leds.c
@@ -22,8 +22,6 @@ 
 static void power_supply_update_bat_leds(struct power_supply *psy)
 {
 	union power_supply_propval status;
-	unsigned long delay_on = 0;
-	unsigned long delay_off = 0;
 
 	if (power_supply_get_property(psy, POWER_SUPPLY_PROP_STATUS, &status))
 		return;
@@ -42,8 +40,7 @@  static void power_supply_update_bat_leds(struct power_supply *psy)
 		led_trigger_event(psy->charging_full_trig, LED_FULL);
 		led_trigger_event(psy->charging_trig, LED_FULL);
 		led_trigger_event(psy->full_trig, LED_OFF);
-		led_trigger_blink(psy->charging_blink_full_solid_trig,
-			&delay_on, &delay_off);
+		led_trigger_blink(psy->charging_blink_full_solid_trig, 0, 0);
 		break;
 	default:
 		led_trigger_event(psy->charging_full_trig, LED_OFF);
diff --git a/drivers/usb/common/led.c b/drivers/usb/common/led.c
index 0865dd44a80a..1de18d90b134 100644
--- a/drivers/usb/common/led.c
+++ b/drivers/usb/common/led.c
@@ -14,8 +14,6 @@ 
 
 #define BLINK_DELAY 30
 
-static unsigned long usb_blink_delay = BLINK_DELAY;
-
 DEFINE_LED_TRIGGER(ledtrig_usb_gadget);
 DEFINE_LED_TRIGGER(ledtrig_usb_host);
 
@@ -32,7 +30,7 @@  void usb_led_activity(enum usb_led_event ev)
 		break;
 	}
 	/* led_trigger_blink_oneshot() handles trig == NULL gracefully */
-	led_trigger_blink_oneshot(trig, &usb_blink_delay, &usb_blink_delay, 0);
+	led_trigger_blink_oneshot(trig, BLINK_DELAY, BLINK_DELAY, 0);
 }
 EXPORT_SYMBOL_GPL(usb_led_activity);
 
diff --git a/include/linux/leds.h b/include/linux/leds.h
index d71201a968b6..6006786cafdc 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -415,11 +415,11 @@  void led_trigger_register_simple(const char *name,
 				struct led_trigger **trigger);
 void led_trigger_unregister_simple(struct led_trigger *trigger);
 void led_trigger_event(struct led_trigger *trigger,  enum led_brightness event);
-void led_trigger_blink(struct led_trigger *trigger, unsigned long *delay_on,
-		       unsigned long *delay_off);
+void led_trigger_blink(struct led_trigger *trigger, unsigned long delay_on,
+		       unsigned long delay_off);
 void led_trigger_blink_oneshot(struct led_trigger *trigger,
-			       unsigned long *delay_on,
-			       unsigned long *delay_off,
+			       unsigned long delay_on,
+			       unsigned long delay_off,
 			       int invert);
 void led_trigger_set_default(struct led_classdev *led_cdev);
 int led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trigger);
@@ -469,11 +469,11 @@  static inline void led_trigger_unregister_simple(struct led_trigger *trigger) {}
 static inline void led_trigger_event(struct led_trigger *trigger,
 				enum led_brightness event) {}
 static inline void led_trigger_blink(struct led_trigger *trigger,
-				      unsigned long *delay_on,
-				      unsigned long *delay_off) {}
+				      unsigned long delay_on,
+				      unsigned long delay_off) {}
 static inline void led_trigger_blink_oneshot(struct led_trigger *trigger,
-				      unsigned long *delay_on,
-				      unsigned long *delay_off,
+				      unsigned long delay_on,
+				      unsigned long delay_off,
 				      int invert) {}
 static inline void led_trigger_set_default(struct led_classdev *led_cdev) {}
 static inline int led_trigger_set(struct led_classdev *led_cdev,
diff --git a/net/mac80211/led.c b/net/mac80211/led.c
index 6de8d0ad5497..2dc732147e85 100644
--- a/net/mac80211/led.c
+++ b/net/mac80211/led.c
@@ -282,7 +282,7 @@  static void tpt_trig_timer(struct timer_list *t)
 		}
 	}
 
-	led_trigger_blink(&local->tpt_led, &on, &off);
+	led_trigger_blink(&local->tpt_led, on, off);
 }
 
 const char *
diff --git a/net/mac80211/led.h b/net/mac80211/led.h
index b71a1428d883..d25f13346b82 100644
--- a/net/mac80211/led.h
+++ b/net/mac80211/led.h
@@ -13,22 +13,18 @@ 
 static inline void ieee80211_led_rx(struct ieee80211_local *local)
 {
 #ifdef CONFIG_MAC80211_LEDS
-	unsigned long led_delay = MAC80211_BLINK_DELAY;
-
 	if (!atomic_read(&local->rx_led_active))
 		return;
-	led_trigger_blink_oneshot(&local->rx_led, &led_delay, &led_delay, 0);
+	led_trigger_blink_oneshot(&local->rx_led, MAC80211_BLINK_DELAY, MAC80211_BLINK_DELAY, 0);
 #endif
 }
 
 static inline void ieee80211_led_tx(struct ieee80211_local *local)
 {
 #ifdef CONFIG_MAC80211_LEDS
-	unsigned long led_delay = MAC80211_BLINK_DELAY;
-
 	if (!atomic_read(&local->tx_led_active))
 		return;
-	led_trigger_blink_oneshot(&local->tx_led, &led_delay, &led_delay, 0);
+	led_trigger_blink_oneshot(&local->tx_led, MAC80211_BLINK_DELAY, MAC80211_BLINK_DELAY, 0);
 #endif
 }
 
diff --git a/net/netfilter/xt_LED.c b/net/netfilter/xt_LED.c
index 66b0f941d8fb..36c9720ad8d6 100644
--- a/net/netfilter/xt_LED.c
+++ b/net/netfilter/xt_LED.c
@@ -43,7 +43,6 @@  led_tg(struct sk_buff *skb, const struct xt_action_param *par)
 {
 	const struct xt_led_info *ledinfo = par->targinfo;
 	struct xt_led_info_internal *ledinternal = ledinfo->internal_data;
-	unsigned long led_delay = XT_LED_BLINK_DELAY;
 
 	/*
 	 * If "always blink" is enabled, and there's still some time until the
@@ -52,7 +51,7 @@  led_tg(struct sk_buff *skb, const struct xt_action_param *par)
 	if ((ledinfo->delay > 0) && ledinfo->always_blink &&
 	    timer_pending(&ledinternal->timer))
 		led_trigger_blink_oneshot(&ledinternal->netfilter_led_trigger,
-					  &led_delay, &led_delay, 1);
+					  XT_LED_BLINK_DELAY, XT_LED_BLINK_DELAY, 1);
 	else
 		led_trigger_event(&ledinternal->netfilter_led_trigger, LED_FULL);