rfkill: don't restore software blocked state on persistent devices

The setting of the "persistent" flag is also made more explicit using
a new rfkill_init_sw_state() function, instead of special-casing
rfkill_set_sw_state() when it is called before registration.

Suspend is a bit of a corner case so we try to get away without adding
another hack to rfkill-input - it's going to be removed soon.
If the state does change over suspend, users will simply have to prod
rfkill-input twice in order to toggle the state.

Userspace policy agents will be able to implement a more consistent user
experience.  For example, they can avoid the above problem if they
toggle devices individually.  Then there would be no "global state"
to get out of sync.

Currently there are only two rfkill drivers with persistent soft-blocked
state.  thinkpad-acpi already checks the software state on resume.
eeepc-laptop will require modification.

Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
CC: Marcel Holtmann <marcel@holtmann.org>
Acked-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 27 insertions, 5 deletions

diff --git a/include/linux/rfkill.h b/include/linux/rfkill.h
index 16e39c7a67f..dcac724340d 100644
--- a/include/linux/rfkill.h
+++ b/include/linux/rfkill.h
@@ -160,8 +160,9 @@ struct rfkill * __must_check rfkill_alloc(const char *name,
  * the rfkill structure. Before calling this function the driver needs
  * to be ready to service method calls from rfkill.
  *
- * If the software blocked state is not set before registration,
- * set_block will be called to initialize it to a default value.
+ * If rfkill_init_sw_state() is not called before registration,
+ * set_block() will be called to initialize the software blocked state
+ * to a default value.
  *
  * If the hardware blocked state is not set before registration,
  * it is assumed to be unblocked.
@@ -234,9 +235,11 @@ bool __must_check rfkill_set_hw_state(struct rfkill *rfkill, bool blocked);
  * rfkill drivers that get events when the soft-blocked state changes
  * (yes, some platforms directly act on input but allow changing again)
  * use this function to notify the rfkill core (and through that also
- * userspace) of the current state.  It is not necessary to notify on
- * resume; since hibernation can always change the soft-blocked state,
- * the rfkill core will unconditionally restore the previous state.
+ * userspace) of the current state.
+ *
+ * Drivers should also call this function after resume if the state has
+ * been changed by the user.  This only makes sense for "persistent"
+ * devices (see rfkill_init_sw_state()).
  *
  * This function can be called in any context, even from within rfkill
  * callbacks.
@@ -247,6 +250,21 @@ bool __must_check rfkill_set_hw_state(struct rfkill *rfkill, bool blocked);
 bool rfkill_set_sw_state(struct rfkill *rfkill, bool blocked);
 
 /**
+ * rfkill_init_sw_state - Initialize persistent software block state
+ * @rfkill: pointer to the rfkill class to modify.
+ * @state: the current software block state to set
+ *
+ * rfkill drivers that preserve their software block state over power off
+ * use this function to notify the rfkill core (and through that also
+ * userspace) of their initial state.  It should only be used before
+ * registration.
+ *
+ * In addition, it marks the device as "persistent".  Persistent devices
+ * are expected to preserve preserve their own state when suspended.
+ */
+void rfkill_init_sw_state(struct rfkill *rfkill, bool blocked);
+
+/**
  * rfkill_set_states - Set the internal rfkill block states
  * @rfkill: pointer to the rfkill class to modify.
  * @sw: the current software block state to set
@@ -307,6 +325,10 @@ static inline bool rfkill_set_sw_state(struct rfkill *rfkill, bool blocked)
 	return blocked;
 }
 
+static inline void rfkill_init_sw_state(struct rfkill *rfkill, bool blocked)
+{
+}
+
 static inline void rfkill_set_states(struct rfkill *rfkill, bool sw, bool hw)
 {
 }