kernel.git/net/mac80211/scan.c, branch linux-2.6.37.y

mac80211: fix sw scan locking

2010-10-07T18:41:27Z

The recent scan overhaul broke locking because now we can jump to code that attempts to unlock, while we don't have the mutex held. Fix this by holding the mutex around all the relevant code. Reported-by: Ben Greear Signed-off-by: Johannes Berg Signed-off-by: John W. Linville

mac80211: avoid uninitialized var warning in ieee80211_scan_cancel

2010-10-06T20:40:40Z

net/mac80211/scan.c: In function ‘ieee80211_scan_cancel’: net/mac80211/scan.c:794: warning: ‘finish’ may be used uninitialized in this function Signed-off-by: John W. Linville

mac80211: compete scan to cfg80211 if deferred scan fail to start

2010-10-06T20:30:42Z

We nulify local->scan_req on failure in __ieee80211_start_scan, so __ieee80211_scan_completed will not call cfg80211_scan_done. Fix that. Signed-off-by: Stanislaw Gruszka Acked-by: Johannes Berg Signed-off-by: John W. Linville

mac80211: do not requeue scan work when not needed

2010-10-06T20:30:42Z

When performing hw scan and not abort it, __ieee80211_scan_completed() is currently called from scan work, so does not need to reschedule work to call drv_hw_scan(). Signed-off-by: Stanislaw Gruszka Acked-by: Johannes Berg Signed-off-by: John W. Linville

mac80211: assure we also cancel deferred scan request

2010-10-06T20:30:42Z

This is partial revert and fix for commit 85f72bc839705294b32b6c16b491c0422f0a71b3 "mac80211: only cancel software-based scans on suspend" When cfg80211 request the scan and mac80211 perform some management work, we defer the scan request. We do not canceling such requests when calling ieee80211_scan_cancel(), because of SCAN_SW_SCANNING bit check just before the call. So fix that problem. Another problem, which commit 85f72bc839705294b32b6c16b491c0422f0a71b3 tries to solve, is we can not cancel HW scan. Hence patch make ieee80211_scan_cancel() ignore HW scan (see code comments). Keeping local->mtx lock assures that the deferred scan will not become "working" HW scan. Signed-off-by: Stanislaw Gruszka Acked-by: Johannes Berg Signed-off-by: John W. Linville

mac80211: keep lock when calling __ieee80211_scan_completed()

2010-10-06T20:30:42Z

We are taking local->mtx inside __ieee80211_scan_completed(), but just before call to that function we drop the lock. Dropping/taking lock is not good, because can lead to hard to understand race conditions. Patch split scan_completed() code into two functions, first must be called with local->mtx taken and second without it. Signed-off-by: Stanislaw Gruszka Acked-by: Johannes Berg Signed-off-by: John W. Linville

mac80211: reduce number of __ieee80211_scan_completed calls

2010-10-06T20:30:41Z

Use goto instruction to call __ieee80211_scan_completed only ones in ieee80211_scan_work. This is prepare for the next patch. Signed-off-by: Stanislaw Gruszka Acked-by: Johannes Berg Signed-off-by: John W. Linville

mac80211: Add DS Parameter Set into Probe Request on 2.4 GHz

2010-09-24T19:54:28Z

IEEE Std 802.11k-2008 added DS Parameter Set information element into Probe Request frames as an optional information on 2.4 GHz band (and mandatory, if radio measurements are enabled). This allows APs to filter out Probe Request frames that may be received from neighboring overlapping channels and by doing so, reduce the number of unnecessary frames in the air. Make mac80211 add this IE into Probe Request frames whenever the channel is known (i.e., whenever hwscan is not used). Signed-off-by: Jouni Malinen Acked-by: Johannes Berg Signed-off-by: John W. Linville

mac80211: Filter ProbeReq SuppRates based on TX rate mask

2010-09-24T19:54:27Z

If the TX rate set has been masked, the removed rates can also be removed from the Supported Rates and Extended Supported Rates IEs in Probe Request frames. Signed-off-by: Jouni Malinen Signed-off-by: John W. Linville

mac80211: allow scan to complete from any context

2010-08-27T17:27:06Z

The ieee80211_scan_completed() function was a frequent source of potential deadlocks, since it is called by drivers but may call back into drivers, so drivers had to make sure to call it without any locks held, which frequently lead to more complex code in drivers. Avoid that problem by allowing the function to be called in any context, and queueing the actual work it does. Also update the documentation for it to indicate this. Signed-off-by: Johannes Berg Signed-off-by: John W. Linville