BMC/Intel-BMC/linux.git/net/mac80211/agg-tx.c, branch dev

mac80211: convert HW flags to unsigned long bitmap

2015-06-10T14:05:36+00:00

As we're running out of hardware capability flags pretty quickly, convert them to use the regular test_bit() style unsigned long bitmaps. This introduces a number of helper functions/macros to set and to test the bits, along with new debugfs code. The occurrences of an explicit __clear_bit() are intentional, the drivers were never supposed to change their supported bits on the fly. We should investigate changing this to be a per-frame flag. Signed-off-by: Johannes Berg

mac80211: add an intermediate software queue implementation

2015-04-01T18:44:34+00:00

This allows drivers to request per-vif and per-sta-tid queues from which they can pull frames. This makes it easier to keep the hardware queues short, and to improve fairness between clients and vifs. The task of scheduling packet transmission is left up to the driver - queueing is controlled by mac80211. Drivers can only dequeue packets by calling ieee80211_tx_dequeue. This makes it possible to add active queue management later without changing drivers using this code. This can also be used as a starting point to implement A-MSDU aggregation in a way that does not add artificially induced latency. Signed-off-by: Felix Fietkau [resolved minor context conflict, minor changes, endian annotations] Signed-off-by: Johannes Berg

mac80211: reject aggregation sessions with non-HT peers

2015-03-30T08:33:19+00:00

If a peer or some local agent (rate control, ...) decides to start an aggregation session but doesn't support HT (which also implies QoS), reject it. This is mostly a corner case as such peers normally won't try to use block-ack sessions and rate control wouldn't start them, but technically QoS stations could request it according to the spec. However, since drivers don't really support such non-HT sessions it's better to reject them. Also, while at it, move the tracing for TX sessions earlier so it captures the error cases as well. Reviewed-by: Emmanuel Grumbach Signed-off-by: Johannes Berg

mac80211: agg-tx: avoid sending DelBA with sta->lock held

2015-03-30T07:46:52+00:00

The rate control locking caused a potential deadlock here due to the locks being acquired in different orders, so that change cannot yet be applied. However, there's no fundamental reason for this code to hold the sta->lock while transmitting frames. Clearly it's better not to hold the lock for longer periods of time, which can happen here since we call all the way down to the driver. Change the code a bit to not hold it while doing that. Signed-off-by: Johannes Berg

mac80211: synchronously reserve TID per station

2014-11-19T17:45:36+00:00

In TDLS (e.g., TDLS off-channel) there is a requirement for some drivers to supply an unused TID between the AP and the device to the FW, to allow sending PTI requests and to allow the FW to aggregate on a specific TID for better throughput. To ensure that the allocated TID is indeed unused, this patch introduces an API for blocking the driver from TXing on that TID. Signed-off-by: Liad Kaufman Signed-off-by: Johannes Berg

mac80211: add WMM admission control support

2014-10-22T08:42:09+00:00

Use the currently existing APIs between mac80211 and the low level driver to implement WMM admission control. The low level driver needs to report the media time used by each transmitted packet in ieee80211_tx_status. Based on that information, mac80211 will modify the QoS parameters of the admission controlled Access Category when the limit is reached. Once the original QoS parameters can be restored, mac80211 will do so. One issue with this approach is that management frames will also erroneously be downgraded, but the upside is that the implementation is simple. In the future, it can be extended to driver- or device-based implementations that are better. Signed-off-by: Emmanuel Grumbach Signed-off-by: Johannes Berg

mac80211: introduce refcount for queue_stop_reasons

2014-06-23T12:22:25+00:00

Sometimes different vifs may be stopping the queues for the same reason (e.g. when several interfaces are performing a channel switch). Instead of using a bitmask for the reasons, use an integer that holds a refcount instead. In order to keep it backwards compatible, introduce a boolean in some functions that tell us whether the queue stopping should be refcounted or not. For now, use not refcounted for all calls to keep it functionally the same as before. Signed-off-by: Luciano Coelho Signed-off-by: Johannes Berg

mac80211: send {ADD,DEL}BA on AC_VO like other mgmt frames, as per spec

2014-02-04T20:48:28+00:00

ATM, {ADD,DEL}BA and BAR frames are sent on the AC matching the TID of the BA parameters. In the discussion [1] about this patch, Johannes recalled that it fixed some races with the DELBA and indeed this behavior was introduced in [2]. While [2] is right for the BARs, the part queueing the {ADD,DEL}BAs on their BA params TID AC violates the spec and is more a workaround for some drivers. Helmut expressed some concerns wrt such drivers, in particular DELBAs in rt2x00. ATM, DELBAs are sent after a driver has called (hence "purposely") ieee80211_start_tx_ba_cb_irqsafe and Johannes and Emmanuel gave some details wrt intentions behind the split of the IEEE80211_AMPDU_TX_STOP_* given to the driver ampdu_action supposed to call this function, which could prove handy to people trying to do the right thing in faulty drivers (if their fw/hw don't get in their way). [1] http://mid.gmane.org/1390391564-18481-1-git-send-email-karl.beldan@gmail.com [2] Commit: cf6bb79ad828 ("mac80211: Use appropriate TID for sending BAR, ADDBA and DELBA frames") Signed-off-by: Karl Beldan Cc: Helmut Schaa Cc: Emmanuel Grumbach Signed-off-by: Johannes Berg

mac80211: fix aggregation state with current drivers

2013-01-24T14:43:51+00:00

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: [] warn_slowpath_common+0x72/0xa0 [] warn_slowpath_fmt+0x33/0x40 [] iwlagn_tx_skb+0xc47/0xce0 [iwldvm] [] iwlagn_mac_tx+0x23/0x40 [iwldvm] [] __ieee80211_tx+0xf6/0x3c0 [mac80211] [] ieee80211_tx+0xd0/0x100 [mac80211] [] ieee80211_xmit+0x96/0xe0 [mac80211] [] ieee80211_subif_start_xmit+0x348/0xc80 [mac80211] [] dev_hard_start_xmit+0x337/0x6d0 [] sch_direct_xmit+0xa9/0x210 [] 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

mac80211: improve aggregation debug messages

2013-01-18T20:55:15+00:00

A lot of the aggregation messages don't indicate the station so they're hard to understand if there are multiple sessions in progress. Make that easier by adding the MAC address to most messages. Also add the TID if it wasn't already there. Signed-off-by: Johannes Berg