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| author | Stanislaw Gruszka <sgruszka@redhat.com> | 2010-07-29 11:37:41 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-08-10 11:09:20 -0700 |
| commit | 5806c0444a387eb4cfecaec74660427f15dfd570 (patch) | |
| tree | fd31c93c828e72f253c6c37a068f2ac30cd8bcec /drivers/net/wireless | |
| parent | 50c144185e4bc848ecdc58cc80113bc48beefdc4 (diff) | |
| download | lwn-5806c0444a387eb4cfecaec74660427f15dfd570.tar.gz lwn-5806c0444a387eb4cfecaec74660427f15dfd570.zip | |
iwlwifi: fix scan abort
commit d28232b461b8d54b09e59325dbac8b0913ce2049 upstream.
Fix possible double priv->mutex lock introduced by commit
a69b03e941abae00380fc6bc1877fb797a1b31e6
"iwlwifi: cancel scan watchdog in iwl_bg_abort_scan" .
We can not call cancel_delayed_work_sync(&priv->scan_check) with
priv->mutex locked because workqueue function iwl_bg_scan_check()
take that lock internally.
We do not need to synchronize when canceling priv->scan_check work.
We can avoid races (sending double abort command or send no
command at all) using STATUS_SCAN_ABORT bit. Moreover
current iwl_bg_scan_check() code seems to be broken, as
we should not send abort commands when currently aborting.
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/net/wireless')
| -rw-r--r-- | drivers/net/wireless/iwlwifi/iwl-scan.c | 18 |
1 files changed, 8 insertions, 10 deletions
diff --git a/drivers/net/wireless/iwlwifi/iwl-scan.c b/drivers/net/wireless/iwlwifi/iwl-scan.c index 386c5f96eff8..e1af9fd5ac3a 100644 --- a/drivers/net/wireless/iwlwifi/iwl-scan.c +++ b/drivers/net/wireless/iwlwifi/iwl-scan.c @@ -420,11 +420,10 @@ void iwl_bg_scan_check(struct work_struct *data) return; mutex_lock(&priv->mutex); - if (test_bit(STATUS_SCANNING, &priv->status) || - test_bit(STATUS_SCAN_ABORTING, &priv->status)) { - IWL_DEBUG_SCAN(priv, "Scan completion watchdog resetting " - "adapter (%dms)\n", - jiffies_to_msecs(IWL_SCAN_CHECK_WATCHDOG)); + if (test_bit(STATUS_SCANNING, &priv->status) && + !test_bit(STATUS_SCAN_ABORTING, &priv->status)) { + IWL_DEBUG_SCAN(priv, "Scan completion watchdog (%dms)\n", + jiffies_to_msecs(IWL_SCAN_CHECK_WATCHDOG)); if (!test_bit(STATUS_EXIT_PENDING, &priv->status)) iwl_send_scan_abort(priv); @@ -489,12 +488,11 @@ void iwl_bg_abort_scan(struct work_struct *work) !test_bit(STATUS_GEO_CONFIGURED, &priv->status)) return; - mutex_lock(&priv->mutex); - - cancel_delayed_work_sync(&priv->scan_check); - set_bit(STATUS_SCAN_ABORTING, &priv->status); - iwl_send_scan_abort(priv); + cancel_delayed_work(&priv->scan_check); + mutex_lock(&priv->mutex); + if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) + iwl_send_scan_abort(priv); mutex_unlock(&priv->mutex); } EXPORT_SYMBOL(iwl_bg_abort_scan); |