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STRUCT TID_AMPDU_TX(9) Internals STRUCT TID_AMPDU_TX(9)

NAME

struct_tid_ampdu_tx - TID aggregation information (Tx).

SYNOPSIS

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;
bool amsdu; };

MEMBERS

rcu_head

rcu head for freeing structure

session_timer

check if we keep Tx-ing on the TID (by timeout value)

addba_resp_timer

timer for peer's response to addba request

pending

pending frames queue -- use sta's spinlock to protect

state

session state (see above)

last_tx

jiffies of last tx activity

timeout

session timeout value to be filled in ADDBA requests

dialog_token

dialog token for aggregation session

stop_initiator

initiator of a session stop

tx_stop

TX DelBA frame when stopping

buf_size

reorder buffer size at receiver

failed_bar_ssn

ssn of the last failed BAR tx attempt

bar_pending

BAR needs to be re-sent

amsdu

support A-MSDU withing A-MDPU

DESCRIPTION

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.

AUTHOR

Johannes Berg <johannes@sipsolutions.net>

Author.

COPYRIGHT

January 2017 Kernel Hackers Manual 4.8.