Commit 2485f710 authored by Johannes Berg's avatar Johannes Berg Committed by John W. Linville

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: default avatarJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 38c07b43
......@@ -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);
......
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