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path: root/net/mac80211/rc80211_minstrel.c
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2013-04-22mac80211/minstrel: use the new rate control APIFelix Fietkau
Pass the rate selection table to mac80211 from minstrel_update_stats. Only rates for sample attempts are set in info->control.rates, with deferred sampling, only the second slot gets changed. Signed-off-by: Felix Fietkau <nbd@openwrt.org> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-04-16mac80211: fix CTS protection handlingFelix Fietkau
The rates[0] CTS and RTS flags are only set after rate control has been called, so minstrel cannot use them to for setting the number of retries. This patch adds two new flags to explicitly indicate RTS/CTS use. Signed-off-by: Felix Fietkau <nbd@openwrt.org> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-03-06mac80211: improve minstrels rate sorting by means of throughput & probabilityThomas Huehn
This patch improves the way minstrel sorts rates according to throughput and success probability. 3 FOR-loops across the entire rate set in function minstrel_update_stats() which where used to determine the fastest, second fastest and most robust rate are reduced to 1 FOR-loop. The sorted list of rates according throughput is extended to the best four rates as we need them in upcoming joint rate and power control. The sorting is done via the new function minstrel_sort_best_tp_rates(). The most robust rate selection is aligned with minstrel_ht's approach. Once any success probability is above 95% the one with the highest throughput is chosen as most robust rate. If success probabilities of all rates are below 95%, the rate with the highest succ. prob. is elected as most robust one Acked-by: Felix Fietkau <nbd@openwrt.org> Signed-off-by: Thomas Huehn <thomas@net.t-labs.tu-berlin.de> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-03-06mac80211: treat minstrel success probabilities below 10% as implausibleThomas Huehn
Based on minstrel_ht this patch treats success probabilities below 10% as implausible values for throughput calculation in minstrel's statistics. Current throughput per rate with such a low success probability is reset to 0 MBit/s. Acked-by: Felix Fietkau <nbd@openwrt.org> Signed-off-by: Thomas Huehn <thomas@net.t-labs.tu-berlin.de> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-03-06mac80211: add lowest rate into minstrel's random rate sampling tableThomas Huehn
While minstrel bootstraps and fills the success probabilities of each rate the lowest rate has typically a very high success probability (often 100% in our tests). Its statistics are never updated but considered to setup the mrr chain. In our tests we see that especially the 3rd mrr stage (which is that rate providing highest success probability) is filled with the lowest rate because its initial high sucess probability is never updated. By design the 4th mrr stage is filled with the lowest rate so often 3rd and 4th mrr stage are equal. This patch follows minstrels general approach of assuming as little as possible about rate dependencies. Consequently we include the lowest rate into the random sampling table to get balanced up-to-date statistics of all rates and therefore balanced decisions. Acked-by: Felix Fietkau <nbd@openwrt.org> Signed-off-by: Thomas Huehn <thomas@net.t-labs.tu-berlin.de> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-03-06mac80211: extend minstrel's rate sampling to avoid unsampled ratesThomas Huehn
Minstrel's decision which rate should be directly sampled within the 1st mrr stage is limited to such rates faster than the current max throughput rate. All rates below the current max. throughput rate are indirectly sampled via the 2nd mrr stage. This approach leads to deprecated per rate statistics and therfore a deprecated mrr chain setup. This patch uses the sampling approach from minstrel_ht. A counter is added to sum all indirect sample attempts per rate. After 20 indirect sampling attempts the rate is directly sampled within the 1st mrr stage. Therefore more up-to-date statistics for all rates are maintained and used to setup the mrr chain. Acked-by: Felix Fietkau <nbd@openwrt.org> Signed-off-by: Thomas Huehn <thomas@net.t-labs.tu-berlin.de> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-03-06mac80211: add documentation and verbose variable names inThomas Huehn
Add documentation and more verbose variable names to minstrel's multi-rate-retry setup within function minstrel_get_rate() to increase the readability of the algorithm. Acked-by: Felix Fietkau <nbd@openwrt.org> Signed-off-by: Thomas Huehn <thomas@net.t-labs.tu-berlin.de> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-03-06mac80211: merge value scaling macros of minstrel_ht and minstrelThomas Huehn
Both minstrel versions use individual ways to scale up integer values to perform calculations. Merge minstrel_ht's scaling macros into minstrels header file and use them in both minstrel versions. Acked-by: Felix Fietkau <nbd@openwrt.org> Signed-off-by: Thomas Huehn <thomas@net.t-labs.tu-berlin.de> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-03-06mac80211: merge EWMA calculation of minstrel_ht and minstrelThomas Huehn
Both rate control algorithms (minstrel and minstrel_ht) calculate averages based on EWMA. Shift function minstrel_ewma() into rc80211_minstrel.h and make use of it in both minstrel version. Also shift the default EWMA level (75%) definition to the header file and clean up variable usage. Acked-by: Felix Fietkau <nbd@openwrt.org> Signed-off-by: Thomas Huehn <thomas@net.t-labs.tu-berlin.de> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-02-13mac80211/minstrel_ht: add support for using CCK ratesFelix Fietkau
When MCS rates start to get bad in 2.4 GHz because of long range or strong interference, CCK rates can be a lot more robust. This patch adds a pseudo MCS group containing CCK rates (long preamble in the lower 4 slots, short preamble in the upper slots). Signed-off-by: Felix Fietkau <nbd@openwrt.org> [make minstrel_ht_get_stats static] Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2012-12-10minstrel: update stats after processing statusJohannes Berg
Instead of updating stats before sending a packet, update them after processing the packet's status. This makes minstrel in line with minstrel_ht. Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2012-04-13mac80211: remove hw.conf.channel usage where possibleMichal Kazior
Removes hw.conf.channel usage from the following functions: * ieee80211_mandatory_rates * ieee80211_sta_get_rates * ieee80211_frame_duration * ieee80211_rts_duration * ieee80211_ctstoself_duration This is in preparation for multi-channel operation. Signed-off-by: Michal Kazior <michal.kazior@tieto.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-11-11minstrel: Remove unused function parameter in calc_rate_durations()Patrick Kelle
Signed-off-by: Patrick Kelle <patrick.kelle81@gmail.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-06-01minstrel_ht: fixed rate mode through debugfsZefir Kurtisi
Found several threads about fixed rate mode in minstrel_ht for test environments, but no patches for it. This patch provides such a mode through debugfs. Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-05-12mac80211: fix contention time computation in minstrel, minstrel_htDaniel Halperin
When transmitting a frame, the transmitter waits a random number of slots between 0 and cw. Thus, the contention time is (cw / 2) * t_slot which we can represent instead as (cw * t_slot) >> 1. Also fix a few other accounting bugs around contention time, and add comments. Signed-off-by: Daniel Halperin <dhalperi@cs.washington.edu> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-07-26minstrel: don't complain about feedback for unrequested ratesJohn W. Linville
"It's not problematic if minstrel gets feedback for rates that it doesn't have in its list, it should just ignore it. - Felix" Signed-off-by: John W. Linville <linville@tuxdriver.com> Cc: Felix Fietkau <nbd@openwrt.org>
2010-04-11Merge branch 'master' of ↵David S. Miller
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/net/stmmac/stmmac_main.c drivers/net/wireless/wl12xx/wl1271_cmd.c drivers/net/wireless/wl12xx/wl1271_main.c drivers/net/wireless/wl12xx/wl1271_spi.c net/core/ethtool.c net/mac80211/scan.c
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-10minstrel: make the rate control ops reusable from another rc implementationFelix Fietkau
This patch makes it possible to reuse the minstrel rate control ops from another rate control module. This is useful in preparing for the new 802.11n implementation of minstrel, which will reuse the old code for legacy stations. Signed-off-by: Felix Fietkau <nbd@openwrt.org> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-09-16rc80211_minstrel: fix contention window calculationPavel Roskin
The contention window is supposed to be a power of two minus one, i.e. 15, 31, 63, 127... minstrel_rate_init() forgets to subtract 1, so the sequence becomes 15, 32, 66, 134... Bug reported by Dan Halperin <dhalperi@cs.washington.edu> Signed-off-by: Pavel Roskin <proski@gnu.org> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-08-20mac80211: Decouple fail_avg stats used by mesh from rate control algorithm.Javier Cardona
Mesh uses the tx failure average to compute the (m)path metric. This used to be done inside the rate control module. This patch breaks the dependency between the mesh stack and the rate control algorithm. Mesh will now work independently of the chosen rate control algorithm. The mesh stack keeps a moving average of the average transmission losses for each mesh peer station. If the fail average exceeds a certain threshold, the peer link is marked as broken. Signed-off-by: Javier Cardona <javier@cozybit.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-08-14mac80211: Early detection of broken mesh paths when using minstrel.Javier Cardona
This change triggers a path discovery as soon as the link quality degrades below a certain threshold. This results in a faster path recovery time than by simply relying on the periodic path refresh mechanism to detect broken links. Signed-off-by: Javier Cardona <javier@cozybit.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-08-14mac80211: Update the station failed frames average when minstrel is used.Javier Cardona
The fail_avg value is used to compute the mesh metric, and was only being set by the pid rate control module. This fixes the mesh path selection mechanism for cards that use mistrel for rate control. Signed-off-by: Javier Cardona <javier@cozybit.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-07-24mac80211: add helper for management / no-ack frame rate decisionLuis R. Rodriguez
All current rate control algorithms agree to send management and no-ack frames at the lowest rate. They also agree to do this when sta and the private rate control data is NULL. We add a hlper to mac80211 for this and simplify the rate control algorithm code. Developers wishing to make enhancements to rate control algorithms are for broadcast/multicast can opt to not use this in their gate_rate() mac80211 callback. Cc: Zhu Yi <yi.zhu@intel.com> Acked-by: Reinette Chatre <reinette.chatre@intel.com> Cc: ipw3945-devel@lists.sourceforge.net Cc: Gabor Juhos <juhosg@openwrt.org> Acked-by: Felix Fietkau <nbd@openwrt.org> Cc: Derek Smithies <derek@indranet.co.nz> Cc: Chittajit Mitra <Chittajit.Mitra@Atheros.com> Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-07-24mac80211: make minstrel/pid RC use ieee80211_is_data(fc)Luis R. Rodriguez
Cc: Felix Fietkau <nbd@openwrt.org> Cc: Derek Smithies <derek@indranet.co.nz> Cc: Chittajit Mitra <Chittajit.Mitra@Atheros.com> Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-07-07mac80211: minstrel: avoid accessing negative indices in rix_to_ndx()Luciano Coelho
If rix is not found in mi->r[], i will become -1 after the loop. This value is eventually used to access arrays, so we were accessing arrays with a negative index, which is obviously not what we want to do. This patch fixes this potential problem. Signed-off-by: Luciano Coelho <luciano.coelho@nokia.com> Acked-by: Felix Fietkau <nbd@openwrt.org> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-06-10mac80211: fix minstrel single-rate memory corruptionBob Copeland
The minstrel rate controller periodically looks up rate indexes in a sampling table. When accessing a specific row and column, minstrel correctly does a bounds check which, on the surface, appears to handle the case where mi->n_rates < 2. However, mi->sample_idx is actually defined as an unsigned, so the right hand side is taken to be a huge positive number when negative, and the check will always fail. Consequently, the RC will overrun the array and cause random memory corruption when communicating with a peer that has only a single rate. The max value of mi->sample_idx is around 25 so casting to int should have no ill effects. Without the change, uptime is a few minutes under load with an AP that has a single hard-coded rate, and both the AP and STA could potentially crash. With the change, both lasted 12 hours with a steady load. Thanks to Ognjen Maric for providing the single-rate clue so I could reproduce this. This fixes http://bugzilla.kernel.org/show_bug.cgi?id=12490 on the regression list (also http://bugzilla.kernel.org/show_bug.cgi?id=13000). Cc: stable@kernel.org Reported-by: Sergey S. Kostyliov <rathamahata@gmail.com> Reported-by: Ognjen Maric <ognjen.maric@gmail.com> Signed-off-by: Bob Copeland <me@bobcopeland.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-05-18Merge branch 'master' of ↵David S. Miller
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/scsi/fcoe/fcoe.c
2009-05-11mac80211: avoid NULL ptr deref when finding max_rates in PID and minstrelJohn W. Linville
"There is another problem with this piece of code. The sband will be NULL after second iteration on single band device and cause null pointer dereference. Everything is working with dual band card. Sorry, but i don't know how to explain this clearly in English. I have looked on the second patch for pid algorithm and found similar bug." Reported-by: Karol Szuster <qflon@o2.pl> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-05-08Merge branch 'master' of ↵David S. Miller
git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next-2.6
2009-05-06mac80211: Fix handling of retry count of NO_ACK frames in minstrelGábor Stefanik
Make the retry count zero (total try count = 1) for frames with IEEE80211_TX_CTL_NO_ACK set. Also remove the check for is_multicast_ether_addr in use_low_rate, which is redundant because all multicasts have IEEE80211_TX_CTL_NO_ACK set. Signed-off-by: Gábor Stefanik <netrolller.3d@gmail.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-05-04mac80211: minstrel, fix memory corruptionJiri Slaby
minstrel doesn't count max rate count in fact, since it doesn't use a loop variable `i' and hence allocs space only for bitrates found in the first band. Fix it by involving the `i' as an index so that it traverses all the bands now and finds the real max bitrate count. Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Cc: Felix Fietkau <nbd@openwrt.org> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-01-12minstrel: fix warning if lowest supported rate index is not 0Christian Lamparter
This patch fixes the following WARNING (caused by rix_to_ndx): " >WARNING: at net/mac80211/rc80211_minstrel.c:69 minstrel_rate_init+0xd2/0x33a [mac80211]() >[...] >Call Trace: > warn_on_slowpath+0x51/0x75 > _format_mac_addr+0x4c/0x88 > minstrel_rate_init+0xd2/0x33a [mac80211] > print_mac+0x16/0x1b > schedule_hrtimeout_range+0xdc/0x107 > ieee80211_add_station+0x158/0x1bd [mac80211] > nl80211_new_station+0x1b3/0x20b [cfg80211] The reason is that I'm experimenting with "g" only mode on a 802.11 b/g card. Therefore rate_lowest_index returns 4 (= 6Mbit, instead of usual 0 = 1Mbit). Since mi->r array is initialized with zeros in minstrel_alloc_sta, rix_to_ndx has a hard time to find the 6Mbit entry and will trigged the WARNING. Signed-off-by: Christian Lamparter <chunkeey@web.de> Acked-by: Felix Fietkau <nbd@openwrt.org> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-11-10wireless: fix a few sparse warningsJohannes Berg
Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-10-31mac80211: remove rate_control_clearJohannes Berg
"Clearing" the rate control algorithm is pointless, none of the algorithms actually uses this operation and it's not even invoked properly for all channel switching. Also, there's no need to since rate control algorithms work per station. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-10-31minstrel: improve performance for non-MRR driversFelix Fietkau
This patch enhances minstrel's performance for non-MRR setups, by preventing it from sampling slower rates with >95% success probability and by putting at least 1 non-sample frame between several sample frames. Signed-off-by: Felix Fietkau <nbd@openwrt.org> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-10-31mac80211/drivers: rewrite the rate control APIJohannes Berg
So after the previous changes we were still unhappy with how convoluted the API is and decided to make things simpler for everybody. This completely changes the rate control API, now taking into account 802.11n with MCS rates and more control, most drivers don't support that though. Signed-off-by: Felix Fietkau <nbd@openwrt.org> Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-10-06mac80211: add the 'minstrel' rate control algorithmFelix Fietkau
Signed-off-by: Felix Fietkau <nbd@openwrt.org> Signed-off-by: John W. Linville <linville@tuxdriver.com>