lwn.git/net/mac80211/util.c, branch doc/4.8-fixes

mac80211: implement fair queueing per txq

2016-06-09T09:34:08+00:00

mac80211's software queues were designed to work very closely with device tx queues. They are required to make use of 802.11 packet aggregation easily and efficiently. Due to the way 802.11 aggregation is designed it only makes sense to keep fair queuing as close to hardware as possible to reduce induced latency and inertia and provide the best flow responsiveness. This change doesn't translate directly to immediate and significant gains. End result depends on driver's induced latency. Best results can be achieved if driver keeps its own tx queue/fifo fill level to a minimum. Signed-off-by: Michal Kazior Signed-off-by: Johannes Berg

mac80211: skip netdev queue control with software queuing

2016-06-09T09:31:27+00:00

Qdiscs are designed with no regard to 802.11 aggregation requirements and hand out packet-by-packet with no guarantee they are destined to the same tid. This does more bad than good no matter how fairly a given qdisc may behave on an ethernet interface. Software queuing used per-AC netdev subqueue congestion control whenever a global AC limit was hit. This meant in practice a single station or tid queue could starve others rather easily. This could resonate with qdiscs in a bad way or could just end up with poor aggregation performance. Increasing the AC limit would increase induced latency which is also bad. Disabling qdiscs by default and performing taildrop instead of netdev subqueue congestion control on the other hand makes it possible for tid queues to fill up "in the meantime" while preventing stations starving each other. This increases aggregation opportunities and should allow software queuing based drivers achieve better performance by utilizing airtime more efficiently with big aggregates. Signed-off-by: Michal Kazior Signed-off-by: Johannes Berg

cfg80211: remove enum ieee80211_band

2016-04-12T13:56:15+00:00

This enum is already perfectly aliased to enum nl80211_band, and the only reason for it is that we get IEEE80211_NUM_BANDS out of it. There's no really good reason to not declare the number of bands in nl80211 though, so do that and remove the cfg80211 one. Signed-off-by: Johannes Berg

mac80211: allow not sending MIC up from driver for HW crypto

2016-04-05T08:48:56+00:00

When HW crypto is used, there's no need for the CCMP/GCMP MIC to be available to mac80211, and the hardware might have removed it already after checking. The MIC is also useless to have when the frame is already decrypted, so allow indicating that it's not present. Since we are running out of bits in mac80211_rx_flags, make the flags field a u64. Signed-off-by: Sara Sharon Signed-off-by: Emmanuel Grumbach Signed-off-by: Johannes Berg

Merge tag 'mac80211-next-for-davem-2016-02-26' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211-next

2016-03-01T22:03:27+00:00

Johannes Berg says: ==================== Here's another round of updates for -next: * big A-MSDU RX performance improvement (avoid linearize of paged RX) * rfkill changes: cleanups, documentation, platform properties * basic PBSS support in cfg80211 * MU-MIMO action frame processing support * BlockAck reordering & duplicate detection offload support * various cleanups & little fixes ==================== Signed-off-by: David S. Miller

mac80211: move MU_MIMO_OWNER flag to ieee80211_vif

2016-02-24T08:04:40+00:00

Drivers may need to track which vif is using VHT MU-MIMO. Move the flag indicationg the ownership of MU_MIMO to ieee80211_vif. Signed-off-by: Sara Sharon Signed-off-by: Emmanuel Grumbach Signed-off-by: Johannes Berg

mac80211: Interoperability workaround for 80+80 and 160 MHz channels

2016-02-24T08:04:32+00:00

Number of deployed 80 MHz capable VHT stations that do not support 80+80 and 160 MHz bandwidths seem to misbehave when trying to connect to an AP that advertises 80+80 or 160 MHz channel bandwidth in the VHT Operation element. To avoid such issues with deployed devices, modify the design based on recently accepted IEEE 802.11 standard changes (*). This allows poorly implemented VHT 80 MHz stations to connect with the AP in 80 MHz mode. 80+80 and 160 MHz capable stations need to support the new workaround mechanism to allow full bandwidth to be used. However, there are more or less no impacted station with 80+80/160 capability deployed. The rebased version of this patch is based on the updated version from Johannes Berg to take the HT/VHT chandef refactoring into account. (*) Changes in https://mentor.ieee.org/802.11/dcn/15/11-15-1530-04-000m-vht160-operation-signaling-through-non-zero-ccfs1.docx were accepted during the IEEE 802.11 January 2016 meeting. Signed-off-by: Jouni Malinen Signed-off-by: Johannes Berg

mac80211: expose txq queue depth and size to drivers

2016-02-24T08:04:30+00:00

This will allow drivers to make more educated decisions whether to defer transmission or not. Relying on wake_tx_queue() call count implicitly was not possible because it could be called without queued frame count actually changing on software tx aggregation start/stop code paths. It was also not possible to know how long byte-wise queue was without dequeueing. Signed-off-by: Michal Kazior Signed-off-by: Johannes Berg

mac80211: add RX_FLAG_MACTIME_PLCP_START

2016-02-24T08:04:27+00:00

The timestamp given by iwlwifi is at the beginning of the frame over the air, at (or during) the SYNC field. Allow such timestamps to be given to mac80211, at least (for now) for frames with non-HT/VHT preambles. Signed-off-by: Johannes Berg

mac80211: refactor HT/VHT to chandef code

2016-02-24T08:04:21+00:00

The station MLME and IBSS/mesh ones use entirely different code for interpreting HT and VHT operation elements. Change the code that interprets them a bit - it now modifies an existing chandef - and use it also in the MLME code. Signed-off-by: Johannes Berg