mac80211: annotate sleeping driver ops
To make it easier to notice cases of calling sleeping ops in atomic context,
annotate driver-ops.h with appropiate might_sleep() calls. At the same time,
also document in mac80211.h the op functions with missing contexts.
mac80211 doesn't seem to use get_tx_stats anywhere currently. Just to be on
the safe side, I documented it to be atomic, but hopefully the op can be
removed in the future.
Compile-tested only.
Signed-off-by: Kalle Valo <kalle.valo@iki.fi>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 08d4135..5ee666a 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -1383,7 +1383,7 @@
* When the device is started it should not have a MAC address
* to avoid acknowledging frames before a non-monitor device
* is added.
- * Must be implemented.
+ * Must be implemented and can sleep.
*
* @stop: Called after last netdevice attached to the hardware
* is disabled. This should turn off the hardware (at least
@@ -1391,7 +1391,7 @@
* May be called right after add_interface if that rejects
* an interface. If you added any work onto the mac80211 workqueue
* you should ensure to cancel it on this callback.
- * Must be implemented.
+ * Must be implemented and can sleep.
*
* @add_interface: Called when a netdevice attached to the hardware is
* enabled. Because it is not called for monitor mode devices, @start
@@ -1401,7 +1401,7 @@
* interface is given in the conf parameter.
* The callback may refuse to add an interface by returning a
* negative error code (which will be seen in userspace.)
- * Must be implemented.
+ * Must be implemented and can sleep.
*
* @remove_interface: Notifies a driver that an interface is going down.
* The @stop callback is called after this if it is the last interface
@@ -1410,19 +1410,20 @@
* must be cleared so the device no longer acknowledges packets,
* the mac_addr member of the conf structure is, however, set to the
* MAC address of the device going away.
- * Hence, this callback must be implemented.
+ * Hence, this callback must be implemented. It can sleep.
*
* @config: Handler for configuration requests. IEEE 802.11 code calls this
* function to change hardware configuration, e.g., channel.
* This function should never fail but returns a negative error code
- * if it does.
+ * if it does. The callback can sleep.
*
* @bss_info_changed: Handler for configuration requests related to BSS
* parameters that may vary during BSS's lifespan, and may affect low
* level driver (e.g. assoc/disassoc status, erp parameters).
* This function should not be used if no BSS has been set, unless
* for association indication. The @changed parameter indicates which
- * of the bss parameters has changed when a call is made.
+ * of the bss parameters has changed when a call is made. The callback
+ * can sleep.
*
* @prepare_multicast: Prepare for multicast filter configuration.
* This callback is optional, and its return value is passed
@@ -1430,20 +1431,22 @@
*
* @configure_filter: Configure the device's RX filter.
* See the section "Frame filtering" for more information.
- * This callback must be implemented.
+ * This callback must be implemented and can sleep.
*
* @set_tim: Set TIM bit. mac80211 calls this function when a TIM bit
* must be set or cleared for a given STA. Must be atomic.
*
* @set_key: See the section "Hardware crypto acceleration"
- * This callback can sleep, and is only called between add_interface
- * and remove_interface calls, i.e. while the given virtual interface
+ * This callback is only called between add_interface and
+ * remove_interface calls, i.e. while the given virtual interface
* is enabled.
* Returns a negative error code if the key can't be added.
+ * The callback can sleep.
*
* @update_tkip_key: See the section "Hardware crypto acceleration"
* This callback will be called in the context of Rx. Called for drivers
* which set IEEE80211_KEY_FLAG_TKIP_REQ_RX_P1_KEY.
+ * The callback can sleep.
*
* @hw_scan: Ask the hardware to service the scan request, no need to start
* the scan state machine in stack. The scan must honour the channel
@@ -1457,21 +1460,28 @@
* When the scan finishes, ieee80211_scan_completed() must be called;
* note that it also must be called when the scan cannot finish due to
* any error unless this callback returned a negative error code.
+ * The callback can sleep.
*
* @sw_scan_start: Notifier function that is called just before a software scan
* is started. Can be NULL, if the driver doesn't need this notification.
+ * The callback can sleep.
*
- * @sw_scan_complete: Notifier function that is called just after a software scan
- * finished. Can be NULL, if the driver doesn't need this notification.
+ * @sw_scan_complete: Notifier function that is called just after a
+ * software scan finished. Can be NULL, if the driver doesn't need
+ * this notification.
+ * The callback can sleep.
*
* @get_stats: Return low-level statistics.
* Returns zero if statistics are available.
+ * The callback can sleep.
*
* @get_tkip_seq: If your device implements TKIP encryption in hardware this
* callback should be provided to read the TKIP transmit IVs (both IV32
* and IV16) for the given key from hardware.
+ * The callback must be atomic.
*
* @set_rts_threshold: Configuration of RTS threshold (if device needs it)
+ * The callback can sleep.
*
* @sta_notify: Notifies low level driver about addition, removal or power
* state transition of an associated station, AP, IBSS/WDS/mesh peer etc.
@@ -1480,30 +1490,36 @@
* @conf_tx: Configure TX queue parameters (EDCF (aifs, cw_min, cw_max),
* bursting) for a hardware TX queue.
* Returns a negative error code on failure.
+ * The callback can sleep.
*
* @get_tx_stats: Get statistics of the current TX queue status. This is used
* to get number of currently queued packets (queue length), maximum queue
* size (limit), and total number of packets sent using each TX queue
* (count). The 'stats' pointer points to an array that has hw->queues
* items.
+ * The callback must be atomic.
*
* @get_tsf: Get the current TSF timer value from firmware/hardware. Currently,
* this is only used for IBSS mode BSSID merging and debugging. Is not a
* required function.
+ * The callback can sleep.
*
* @set_tsf: Set the TSF timer to the specified value in the firmware/hardware.
* Currently, this is only used for IBSS mode debugging. Is not a
* required function.
+ * The callback can sleep.
*
* @reset_tsf: Reset the TSF timer and allow firmware/hardware to synchronize
* with other STAs in the IBSS. This is only used in IBSS mode. This
* function is optional if the firmware/hardware takes full care of
* TSF synchronization.
+ * The callback can sleep.
*
* @tx_last_beacon: Determine whether the last IBSS beacon was sent by us.
* This is needed only for IBSS mode and the result of this function is
* used to determine whether to reply to Probe Requests.
* Returns non-zero if this device sent the last beacon.
+ * The callback can sleep.
*
* @ampdu_action: Perform a certain A-MPDU action
* The RA/TID combination determines the destination and TID we want
@@ -1512,16 +1528,19 @@
* is the first frame we expect to perform the action on. Notice
* that TX/RX_STOP can pass NULL for this parameter.
* Returns a negative error code on failure.
+ * The callback must be atomic.
*
* @rfkill_poll: Poll rfkill hardware state. If you need this, you also
* need to set wiphy->rfkill_poll to %true before registration,
* and need to call wiphy_rfkill_set_hw_state() in the callback.
+ * The callback can sleep.
*
* @testmode_cmd: Implement a cfg80211 test mode command.
+ * The callback can sleep.
*
* @flush: Flush all pending frames from the hardware queue, making sure
* that the hardware queues are empty. If the parameter @drop is set
- * to %true, pending frames may be dropped.
+ * to %true, pending frames may be dropped. The callback can sleep.
*/
struct ieee80211_ops {
int (*tx)(struct ieee80211_hw *hw, struct sk_buff *skb);