struct tid_ampdu_tx — TID aggregation information (Tx).
struct tid_ampdu_tx {
struct rcu_head rcu_head;
struct timer_list session_timer;
struct timer_list addba_resp_timer;
struct sk_buff_head pending;
unsigned long state;
unsigned long last_tx;
u16 timeout;
u8 dialog_token;
u8 stop_initiator;
bool tx_stop;
u8 buf_size;
u16 failed_bar_ssn;
bool bar_pending;
}; rcu head for freeing structure
check if we keep Tx-ing on the TID (by timeout value)
timer for peer's response to addba request
pending frames queue -- use sta's spinlock to protect
session state (see above)
jiffies of last tx activity
session timeout value to be filled in ADDBA requests
dialog token for aggregation session
initiator of a session stop
TX DelBA frame when stopping
reorder buffer size at receiver
ssn of the last failed BAR tx attempt
BAR needs to be re-sent
This structure's lifetime is managed by RCU, assignments to the array holding it must hold the aggregation mutex.
The TX path can access it under RCU lock-free if, and
only if, the state has the flag HT_AGG_STATE_OPERATIONAL
set. Otherwise, the TX path must also acquire the spinlock
and re-check the state, see comments in the tx code
touching it.