Add a new "global" (i.e. not per-rfkill device) LED trigger, rfkill-any,
which may be useful on laptops with a single "radio LED" and multiple
radio transmitters. The trigger is meant to turn a LED on whenever
there is at least one radio transmitter active and turn it off
otherwise.
Signed-off-by: Michał Kępień <kernel@xxxxxxxxxx>
---
Changes from v3:
- Revert introducing a new bitfield and instead defer LED event firing
to a work queue to prevent conditional locking and ensure the
trigger can really be used from any context. This also voids the
need to take rfkill_global_mutex before calling rfkill_set_block()
in rfkill_resume().
Changes from v2:
- Handle the global mutex properly when rfkill_set_{hw,sw}_state() or
rfkill_set_states() is called from within an rfkill callback. v2
always tried to lock the global mutex in such a case, which led to a
deadlock when an rfkill driver called one of the above functions
from its query or set_block callback. This is solved by defining a
new bitfield, RFKILL_BLOCK_SW_HASLOCK, which is set before the above
callbacks are invoked and cleared afterwards; the functions listed
above use this bitfield to tell rfkill_any_led_trigger_event()
whether the global mutex is currently held or not.
RFKILL_BLOCK_SW_SETCALL cannot be reused for this purpose as setting
it before invoking the query callback would cause any calls to
rfkill_set_sw_state() made from within that callback to work on
RFKILL_BLOCK_SW_PREV instead of RFKILL_BLOCK_SW and thus change the
way rfkill_set_block() behaves.
- As rfkill_any_led_trigger_event() now takes a boolean argument which
tells it whether the global mutex was already taken by the caller,
all calls to __rfkill_any_led_trigger_event() outside
rfkill_any_led_trigger_event() have been replaced with calls to
rfkill_any_led_trigger_event(true).
Changes from v1:
- take rfkill_global_mutex before calling rfkill_set_block() in
rfkill_resume(); the need for doing this was previously obviated by
908209c ("rfkill: don't impose global states on resume"), but given
that __rfkill_any_led_trigger_event() is called from
rfkill_set_block() unconditionally, each caller of the latter needs
to take care of locking rfkill_global_mutex,
- declare __rfkill_any_led_trigger_event() even when
CONFIG_RFKILL_LEDS=n to prevent implicit declaration errors,
- remove the #ifdef surrounding rfkill_any_led_trigger_{,un}register()
calls to prevent compilation warnings about functions and a label
being defined but not used,
- move the rfkill_any_led_trigger_register() call in rfkill_init()
before the rfkill_handler_init() call to avoid the need to call
rfkill_handler_exit() from rfkill_init() and thus prevent a section
mismatch.
net/rfkill/core.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 71 insertions(+), 1 deletion(-)
diff --git a/net/rfkill/core.c b/net/rfkill/core.c
index afa4f71b4c7b..2064c3a35ef8 100644
--- a/net/rfkill/core.c
+++ b/net/rfkill/core.c
@@ -176,6 +176,50 @@ static void rfkill_led_trigger_unregister(struct rfkill *rfkill)
{
led_trigger_unregister(&rfkill->led_trigger);
}
+
+static struct led_trigger rfkill_any_led_trigger;
+static struct work_struct rfkill_any_work;
+
+static void rfkill_any_led_trigger_worker(struct work_struct *work)
+{
+ enum led_brightness brightness = LED_OFF;
+ struct rfkill *rfkill;
+
+ mutex_lock(&rfkill_global_mutex);
+ list_for_each_entry(rfkill, &rfkill_list, node) {
+ if (!(rfkill->state & RFKILL_BLOCK_ANY)) {
+ brightness = LED_FULL;
+ break;
+ }
+ }
+ mutex_unlock(&rfkill_global_mutex);
+
+ led_trigger_event(&rfkill_any_led_trigger, brightness);
+}
+
+static void rfkill_any_led_trigger_event(void)
+{
+ schedule_work(&rfkill_any_work);
+}
+
+static void rfkill_any_led_trigger_activate(struct led_classdev *led_cdev)
+{
+ rfkill_any_led_trigger_event();
+}
+
+static int rfkill_any_led_trigger_register(void)
+{
+ INIT_WORK(&rfkill_any_work, rfkill_any_led_trigger_worker);
+ rfkill_any_led_trigger.name = "rfkill-any";
+ rfkill_any_led_trigger.activate = rfkill_any_led_trigger_activate;
+ return led_trigger_register(&rfkill_any_led_trigger);
+}
+
+static void rfkill_any_led_trigger_unregister(void)
+{
+ led_trigger_unregister(&rfkill_any_led_trigger);
+ cancel_work_sync(&rfkill_any_work);
+}
#else
static void rfkill_led_trigger_event(struct rfkill *rfkill)
{
@@ -189,6 +233,19 @@ static inline int rfkill_led_trigger_register(struct rfkill *rfkill)
static inline void rfkill_led_trigger_unregister(struct rfkill *rfkill)
{
}
+
+static void rfkill_any_led_trigger_event(void)
+{
+}
+
+static int rfkill_any_led_trigger_register(void)
+{
+ return 0;
+}
+
+static void rfkill_any_led_trigger_unregister(void)
+{
+}
#endif /* CONFIG_RFKILL_LEDS */
static void rfkill_fill_event(struct rfkill_event *ev, struct rfkill *rfkill,
@@ -297,6 +354,7 @@ static void rfkill_set_block(struct rfkill *rfkill, bool blocked)
spin_unlock_irqrestore(&rfkill->lock, flags);
rfkill_led_trigger_event(rfkill);
+ rfkill_any_led_trigger_event();
if (prev != curr)
rfkill_event(rfkill);
@@ -477,6 +535,7 @@ bool rfkill_set_hw_state(struct rfkill *rfkill, bool blocked)
spin_unlock_irqrestore(&rfkill->lock, flags);
rfkill_led_trigger_event(rfkill);
+ rfkill_any_led_trigger_event();
if (rfkill->registered && prev != blocked)
schedule_work(&rfkill->uevent_work);
@@ -520,6 +579,7 @@ bool rfkill_set_sw_state(struct rfkill *rfkill, bool blocked)
schedule_work(&rfkill->uevent_work);
rfkill_led_trigger_event(rfkill);
+ rfkill_any_led_trigger_event();
return blocked;
}
@@ -569,6 +629,7 @@ void rfkill_set_states(struct rfkill *rfkill, bool sw, bool hw)
schedule_work(&rfkill->uevent_work);
rfkill_led_trigger_event(rfkill);
+ rfkill_any_led_trigger_event();
}
}
EXPORT_SYMBOL(rfkill_set_states);
@@ -985,6 +1046,7 @@ int __must_check rfkill_register(struct rfkill *rfkill)
#endif
}
+ rfkill_any_led_trigger_event();
rfkill_send_events(rfkill, RFKILL_OP_ADD);
mutex_unlock(&rfkill_global_mutex);
@@ -1017,6 +1079,7 @@ void rfkill_unregister(struct rfkill *rfkill)
mutex_lock(&rfkill_global_mutex);
rfkill_send_events(rfkill, RFKILL_OP_DEL);
list_del_init(&rfkill->node);
+ rfkill_any_led_trigger_event();
mutex_unlock(&rfkill_global_mutex);
rfkill_led_trigger_unregister(rfkill);
@@ -1269,6 +1332,10 @@ static int __init rfkill_init(void)
if (error)
goto error_misc;
+ error = rfkill_any_led_trigger_register();
+ if (error)
+ goto error_led_trigger;
+
#ifdef CONFIG_RFKILL_INPUT
error = rfkill_handler_init();
if (error)
@@ -1279,8 +1346,10 @@ static int __init rfkill_init(void)
#ifdef CONFIG_RFKILL_INPUT
error_input:
- misc_deregister(&rfkill_miscdev);
+ rfkill_any_led_trigger_unregister();
#endif
+error_led_trigger:
+ misc_deregister(&rfkill_miscdev);
error_misc:
class_unregister(&rfkill_class);
error_class:
@@ -1293,6 +1362,7 @@ static void __exit rfkill_exit(void)
#ifdef CONFIG_RFKILL_INPUT
rfkill_handler_exit();
#endif
+ rfkill_any_led_trigger_unregister();
misc_deregister(&rfkill_miscdev);
class_unregister(&rfkill_class);
}
--
2.11.0
