Return-path: Received: from fg-out-1718.google.com ([72.14.220.158]:55677 "EHLO fg-out-1718.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753729AbZCXRvW convert rfc822-to-8bit (ORCPT ); Tue, 24 Mar 2009 13:51:22 -0400 Received: by fg-out-1718.google.com with SMTP id 16so591976fgg.17 for ; Tue, 24 Mar 2009 10:51:19 -0700 (PDT) From: Helmut Schaa To: TJ Subject: Re: iwl3945: Don't queue rfkill_poll work when module is exiting Date: Tue, 24 Mar 2009 18:51:11 +0100 Cc: Reinette Chatre , linux-wireless@vger.kernel.org References: <1237909459.5365.16.camel@hephaestion> In-Reply-To: <1237909459.5365.16.camel@hephaestion> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Message-Id: <200903241851.11949.helmut.schaa@gmail.com> (sfid-20090324_185126_285363_7F36121F) Sender: linux-wireless-owner@vger.kernel.org List-ID: Am Dienstag, 24. M=E4rz 2009 schrieb TJ: > Tim Gardner suggested I forward this as a possible stable-release > update. I found the problem in our current Ubuntu Jaunty tree - iwlwi= fi > version 1.2.26k. What follows is a copy of the patch for Jaunty > (2.6.28). The patch that introduced the rfkill polling did not hit mainline yet. = It should pop up in 2.6.30, hence this patch is not needed for any stable series. I wasn't able to reproduce the issue by unloading iwl3945 here. Any hin= ts on how to reproduce this issue? Thanks, Helmut > ---------- > Bug: #345710 >=20 > When the wireless interface is active and the iwl3945 module is unloa= ded the > call to ieee80211_unregister_hw() would call iwl3945_mac_stop() which= would > restart the delayed workqueue for rfkill_poll. That workqueue had alr= eady been > cancelled so when the next work item was run (2 seconds later) the sy= stem would > suffer a hard lock-up because the module had been unloaded by then. >=20 > This patch implements STATUS_EXIT_PENDING checks in places where the = rfkill_poll > work is scheduled, and moves the final workqueue cancellation to occu= r after the > call to ieee80211_unregister_hw(). >=20 > Bug discovered, experienced and fix tested on my PC. >=20 > Signed-off-by: TJ > --- > drivers/net/wireless/iwlwifi/iwl3945-base.c | 16 +++++++++++++--- > 1 files changed, 13 insertions(+), 3 deletions(-) >=20 > diff --git a/drivers/net/wireless/iwlwifi/iwl3945-base.c b/drivers/ne= t/wireless/iwlwifi/iwl3945-base.c > index bb92db2..acaf038 100644 > --- a/drivers/net/wireless/iwlwifi/iwl3945-base.c > +++ b/drivers/net/wireless/iwlwifi/iwl3945-base.c > @@ -6062,7 +6062,9 @@ static void iwl3945_rfkill_poll(struct work_str= uct *data) > if (test_bit(STATUS_RF_KILL_HW, &status) !=3D test_bit(STATUS_RF_KI= LL_HW, &priv->status)) > queue_work(priv->workqueue, &priv->rf_kill); > =20 > - queue_delayed_work(priv->workqueue, &priv->rfkill_poll, > + /* only queue if module isn't exiting */ > + if (! test_bit(STATUS_EXIT_PENDING, &priv->status)) > + queue_delayed_work(priv->workqueue, &priv->rfkill_poll, > round_jiffies_relative(2 * HZ)); > =20 > } > @@ -6588,7 +6590,10 @@ static void iwl3945_mac_stop(struct ieee80211_= hw *hw) > flush_workqueue(priv->workqueue); > =20 > /* start polling the killswitch state again */ > - queue_delayed_work(priv->workqueue, &priv->rfkill_poll, > + > + /* only queue if module isn't exiting */ > + if (! test_bit(STATUS_EXIT_PENDING, &priv->status)) > + queue_delayed_work(priv->workqueue, &priv->rfkill_poll, > round_jiffies_relative(2 * HZ)); > =20 > IWL_DEBUG_MAC80211("leave\n"); > @@ -8166,7 +8171,6 @@ static void __devexit iwl3945_pci_remove(struct= pci_dev *pdev) > sysfs_remove_group(&pdev->dev.kobj, &iwl3945_attribute_group); > =20 > iwl3945_rfkill_unregister(priv); > - cancel_delayed_work(&priv->rfkill_poll); > iwl3945_dealloc_ucode_pci(priv); > =20 > if (priv->rxq.bd) > @@ -8182,6 +8186,12 @@ static void __devexit iwl3945_pci_remove(struc= t pci_dev *pdev) > /*netif_stop_queue(dev); */ > flush_workqueue(priv->workqueue); > =20 > + /* ieee80211_unregister_hw calls iwl3945_mac_stop which used to res= tart the rfkill > + polling. Although that now checks STATUS_EXIT_PENDING do cancel = and wait for any > + pending work to complete */ > + cancel_delayed_work(&priv->rfkill_poll); > + cancel_work_sync(&priv->rfkill_poll); > + > /* ieee80211_unregister_hw calls iwl3945_mac_stop, which flushes > * priv->workqueue... so we can't take down the workqueue > * until now... */ -- To unsubscribe from this list: send the line "unsubscribe linux-wireles= s" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html