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authorJohannes Berg <johannes@sipsolutions.net>2008-02-25 16:27:41 +0100
committerJohn W. Linville <linville@tuxdriver.com>2008-02-29 15:41:58 -0500
commit2485f7105f20f85c2dbebc67be6b2cb97175fa7e (patch)
treec8c620864bb220d8a299d7f45675334879eb742a /include/net
parent38c07b430b50172b803fe4c7f76cba580ba9931f (diff)
mac80211: clarify use of TX status/RX callbacks
This patch clarifies the use of the irqsafe vs. non-irq-safe functions and their respective locking requirements. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'include/net')
-rw-r--r--include/net/mac80211.h37
1 files changed, 34 insertions, 3 deletions
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index cd4b1c1a0d4..7a80c398123 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -38,7 +38,11 @@
* called in hardware interrupt context. The low-level driver must not call any
* other functions in hardware interrupt context. If there is a need for such
* call, the low-level driver should first ACK the interrupt and perform the
- * IEEE 802.11 code call after this, e.g. from a scheduled workqueue function.
+ * IEEE 802.11 code call after this, e.g. from a scheduled workqueue or even
+ * tasklet function.
+ *
+ * NOTE: If the driver opts to use the _irqsafe() functions, it may not also
+ * use the non-irqsafe functions!
*/
/**
@@ -1204,7 +1208,10 @@ void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
* buffer in @skb must start with an IEEE 802.11 header or a radiotap
* header if %RX_FLAG_RADIOTAP is set in the @status flags.
*
- * This function may not be called in IRQ context.
+ * This function may not be called in IRQ context. Calls to this function
+ * for a single hardware must be synchronized against each other. Calls
+ * to this function and ieee80211_rx_irqsafe() may not be mixed for a
+ * single hardware.
*
* @hw: the hardware this frame came in on
* @skb: the buffer to receive, owned by mac80211 after this call
@@ -1221,7 +1228,10 @@ static inline void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
* ieee80211_rx_irqsafe - receive frame
*
* Like ieee80211_rx() but can be called in IRQ context
- * (internally defers to a workqueue.)
+ * (internally defers to a tasklet.)
+ *
+ * Calls to this function and ieee80211_rx() may not be mixed for a
+ * single hardware.
*
* @hw: the hardware this frame came in on
* @skb: the buffer to receive, owned by mac80211 after this call
@@ -1240,6 +1250,11 @@ void ieee80211_rx_irqsafe(struct ieee80211_hw *hw,
* transmitted. It is permissible to not call this function for
* multicast frames but this can affect statistics.
*
+ * This function may not be called in IRQ context. Calls to this function
+ * for a single hardware must be synchronized against each other. Calls
+ * to this function and ieee80211_tx_status_irqsafe() may not be mixed
+ * for a single hardware.
+ *
* @hw: the hardware the frame was transmitted by
* @skb: the frame that was transmitted, owned by mac80211 after this call
* @status: status information for this frame; the status pointer need not
@@ -1249,6 +1264,22 @@ void ieee80211_rx_irqsafe(struct ieee80211_hw *hw,
void ieee80211_tx_status(struct ieee80211_hw *hw,
struct sk_buff *skb,
struct ieee80211_tx_status *status);
+
+/**
+ * ieee80211_tx_status_irqsafe - irq-safe transmit status callback
+ *
+ * Like ieee80211_tx_status() but can be called in IRQ context
+ * (internally defers to a tasklet.)
+ *
+ * Calls to this function and ieee80211_tx_status() may not be mixed for a
+ * single hardware.
+ *
+ * @hw: the hardware the frame was transmitted by
+ * @skb: the frame that was transmitted, owned by mac80211 after this call
+ * @status: status information for this frame; the status pointer need not
+ * be valid after this function returns and is not freed by mac80211,
+ * it is recommended that it points to a stack area
+ */
void ieee80211_tx_status_irqsafe(struct ieee80211_hw *hw,
struct sk_buff *skb,
struct ieee80211_tx_status *status);