mirror of https://gitee.com/openkylin/linux.git
8147dc7f54
For drivers that don't actually flush their queues when aggregation stop with the IEEE80211_AMPDU_TX_STOP_FLUSH or IEEE80211_AMPDU_TX_STOP_FLUSH_CONT reasons is done, like iwlwifi or iwlegacy, mac80211 can then transmit on a TID that the driver still considers busy. This happens in the following way: - IEEE80211_AMPDU_TX_STOP_FLUSH requested - driver marks TID as emptying - mac80211 removes tid_tx data, this can copy packets to the TX pending queues and also let new packets through to the driver - driver gets unexpected TX as it wasn't completely converted to the new API In iwlwifi, this lead to the following warning: WARNING: at drivers/net/wireless/iwlwifi/dvm/tx.c:442 iwlagn_tx_skb+0xc47/0xce0 Tx while agg.state = 4 Modules linked in: [...] Pid: 0, comm: kworker/0:0 Tainted: G W 3.1.0 #1 Call Trace: [<c1046e42>] warn_slowpath_common+0x72/0xa0 [<c1046f13>] warn_slowpath_fmt+0x33/0x40 [<fddffa17>] iwlagn_tx_skb+0xc47/0xce0 [iwldvm] [<fddfcaa3>] iwlagn_mac_tx+0x23/0x40 [iwldvm] [<fd8c98b6>] __ieee80211_tx+0xf6/0x3c0 [mac80211] [<fd8cbe00>] ieee80211_tx+0xd0/0x100 [mac80211] [<fd8cc176>] ieee80211_xmit+0x96/0xe0 [mac80211] [<fd8cc578>] ieee80211_subif_start_xmit+0x348/0xc80 [mac80211] [<c1445207>] dev_hard_start_xmit+0x337/0x6d0 [<c145eee9>] sch_direct_xmit+0xa9/0x210 [<c14462c0>] dev_queue_xmit+0x1b0/0x8e0 Fortunately, solving this problem is easy as the station is being destroyed, so such transmit packets can only happen due to races. Instead of trying to close the race just let the race not reach the drivers by making two changes: 1) remove the explicit aggregation session teardown in the managed mode code, the same thing will be done when the station is removed, in __sta_info_destroy. 2) When aggregation stop with AGG_STOP_DESTROY_STA is requested, leave the tid_tx data around as stopped. It will be cleared and freed in cleanup_single_sta later, but until then any racy packets will be put onto the tid_tx pending queue instead of transmitted which is fine since the station is being removed. Signed-off-by: Johannes Berg <johannes.berg@intel.com> |
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| 9p | ||
| 802 | ||
| 8021q | ||
| appletalk | ||
| atm | ||
| ax25 | ||
| batman-adv | ||
| bluetooth | ||
| bridge | ||
| caif | ||
| can | ||
| ceph | ||
| core | ||
| dcb | ||
| dccp | ||
| decnet | ||
| dns_resolver | ||
| dsa | ||
| ethernet | ||
| ieee802154 | ||
| ipv4 | ||
| ipv6 | ||
| ipx | ||
| irda | ||
| iucv | ||
| key | ||
| l2tp | ||
| lapb | ||
| llc | ||
| mac80211 | ||
| mac802154 | ||
| netfilter | ||
| netlabel | ||
| netlink | ||
| netrom | ||
| nfc | ||
| openvswitch | ||
| packet | ||
| phonet | ||
| rds | ||
| rfkill | ||
| rose | ||
| rxrpc | ||
| sched | ||
| sctp | ||
| sunrpc | ||
| tipc | ||
| unix | ||
| wanrouter | ||
| wimax | ||
| wireless | ||
| x25 | ||
| xfrm | ||
| Kconfig | ||
| Makefile | ||
| compat.c | ||
| nonet.c | ||
| socket.c | ||
| sysctl_net.c | ||