linux.git/net/mac80211/debugfs_sta.c, branch v2.6.27

mac80211: remove channel use statistics

2008-05-22T01:48:17+00:00

The useless channel use statistics are quite a lot of code, currently
use integer divisions in the packet fast path, are rather inaccurate
since they do not account for retries and finally nobody even cares.
Hence, remove them completely.

Signed-off-by: Johannes Berg 
Signed-off-by: John W. Linville

mac80211: use hardware flags for signal/noise units

2008-05-14T20:29:49+00:00

trying to clean up the signal/noise code. the previous code in mac80211 had
confusing names for the related variables, did not have much definition of
what units of signal and noise were provided and used implicit mechanisms from
the wireless extensions.

this patch introduces hardware capability flags to let the hardware specify
clearly if it can provide signal and noise level values and which units it can
provide. this also anticipates possible new units like RCPI in the future.

for signal:

  IEEE80211_HW_SIGNAL_UNSPEC - unspecified, unknown, hw specific
  IEEE80211_HW_SIGNAL_DB     - dB difference to unspecified reference point
  IEEE80211_HW_SIGNAL_DBM    - dBm, difference to 1mW

for noise we currently only have dBm:

  IEEE80211_HW_NOISE_DBM     - dBm, difference to 1mW

if IEEE80211_HW_SIGNAL_UNSPEC or IEEE80211_HW_SIGNAL_DB is used the driver has
to provide the maximum value (max_signal) it reports in order for applications
to make sense of the signal values.

i tried my best to find out for each driver what it can provide and update it
but i'm not sure (?) for some of them and used the more conservative guess in
doubt. this can be fixed easily after this patch has been merged by changing
the hardware flags of the driver.

DRIVER          SIGNAL    MAX	NOISE   QUAL
-----------------------------------------------------------------
adm8211         unspec(?) 100   n/a     missing
at76_usb        unspec(?) (?)   unused  missing
ath5k           dBm             dBm     percent rssi
b43legacy       dBm             dBm     percent jssi(?)
b43             dBm             dBm     percent jssi(?)
iwl-3945        dBm             dBm     percent snr+more
iwl-4965        dBm             dBm     percent snr+more
p54             unspec    127   n/a     missing
rt2x00          dBm	        n/a     percent rssi+tx/rx frame success
  rt2400        dBm             n/a
  rt2500pci     dBm             n/a
  rt2500usb     dBm             n/a
  rt61pci       dBm             n/a
  rt73usb       dBm             n/a
rtl8180         unspec(?) 65    n/a     (?)
rtl8187         unspec(?) 65    (?)     noise(?)
zd1211          dB(?)     100   n/a     percent

drivers/net/wireless/ath5k/base.c:      Changes-licensed-under: 3-Clause-BSD

Signed-off-by: Bruno Randolf 
Signed-off-by: John W. Linville

mac80211: proper STA info locking

2008-05-14T20:29:34+00:00

As discussed earlier, we can unify locking in struct sta_info
and use just a single spinlock protecting all members of the
structure that need protection. Many don't, but one of the
especially bad ones is the 'flags' member that can currently
be clobbered when RX and TX is being processed on different
CPUs at the same time.

Because having four spinlocks for different, mostly exclusive
parts of a single structure is overkill, this patch also kills
the ampdu and mesh plink spinlocks and uses just a single one
for everything. Because none of the spinlocks are nested, this
is safe.

It remains to be seen whether or not we should make the sta
flags use atomic bit operations instead, for now though this
is a safe thing and using atomic operations instead will be
very simple using the new static inline functions this patch
introduces for accessing sta->flags.

Since spin_lock_bh() is used with this lock, there shouldn't
be any contention even if aggregation is enabled at around the
same time as both requires frame transmission/reception which
is in a bh context.

Signed-off-by: Johannes Berg 
Cc: Tomas Winkler 
Cc: Ron Rindjunsky 
Cc: Luis Carlos Cobo 
Signed-off-by: John W. Linville

mac80211: QoS related cleanups

2008-05-07T19:02:26+00:00

This
 * makes the queue number passed to drivers a u16
   (as it will be with skb_get_queue_mapping)
 * removes the useless queue number defines
 * splits hw->queues into hw->queues/ampdu_queues
 * removes the debugfs files for per-queue counters
 * removes some dead QoS code
 * removes the beacon queue configuration for IBSS
   so that the drivers now never get a queue number
   bigger than (hw->queues + hw->ampdu_queues - 1)
   for tx and only in the range 0..hw->queues-1 for
   conf_tx.

Signed-off-by: Johannes Berg 
Signed-off-by: John W. Linville

mac80211: make debugfs files root-only

2008-04-08T20:44:43+00:00

Unfortunately, debugfs can be made to access invalid memory by
open()ing a file and then waiting until the corresponding debugfs
file has been removed (and, probably, the underlying object.)

That could be exploited by any user if the user is able to open
debugfs files and can cause networking devices, STA entries or
similar to disappear which is quite easy to do.

Hence, all debugfs files should be root-only.

Signed-off-by: Johannes Berg 
Signed-off-by: John W. Linville

mac80211: A-MPDU MLME use dynamic allocation

2008-03-27T20:03:20+00:00

This patch alters the A-MPDU MLME in sta_info to use dynamic allocation,
thus drastically improving memory usage - from a constant ~2 Kbyte in
the previous (static) allocation to a lower limit of ~200 Byte and an upper
limit of ~2 Kbyte.

Signed-off-by: Ron Rindjunsky 
Signed-off-by: Tomas Winkler 
Signed-off-by: John W. Linville

mac80211: fix wrong Rx A-MPDU control via debugfs

2008-03-27T20:03:17+00:00

This patch eliminate the use of buf_size as a trigger in favor of a new
flag to control Rx A-MPDU sessions through debugfs

Signed-off-by: Ron Rindjunsky 
Signed-off-by: Tomas Winkler 
Signed-off-by: John W. Linville

mac80211: clean up sta_info and document locking

2008-03-06T20:30:47+00:00

This patch cleans up the sta_info struct and documents how
each set of variables is locked. Notably, flags locking is
completely missing. It also adds kernel-doc for some (but
not all yet) members of the struct.

Signed-off-by: Johannes Berg 
Signed-off-by: John W. Linville

mac80211: RCU-ify STA info structure access

2008-03-06T20:30:46+00:00

This makes access to the STA hash table/list use RCU to protect
against freeing of items. However, it's not a true RCU, the
copy step is missing: whenever somebody changes a STA item it
is simply updated. This is an existing race condition that is
now somewhat understandable.

This patch also fixes the race key freeing vs. STA destruction
by making sure that sta_info_destroy() is always called under
RTNL and frees the key.

Signed-off-by: Johannes Berg 
Signed-off-by: John W. Linville

mac80211: remove STA infos last_ack stuff

2008-02-29T20:42:02+00:00

These things aren't used and the only possible use is within
rate control algorithms, however those can, if they need it,
keep track of it in their private data. last_ack_ms isn't
even updated so completely useless.

Signed-off-by: Johannes Berg 
Signed-off-by: John W. Linville