[Jaunty SRU] LP#345710 iwl3945: cancel rfkill_poll with sync when the module is exiting

[Tim Gardner]

Huaxu Wan wrote:
> From f3628f0ac6c9713afadaa9654815c37a294ce7e2 Mon Sep 17 00:00:00 2001
> From: Huaxu Wan <huaxu.wan at linux.intel.com>
> Date: Fri, 8 May 2009 07:36:58 -0400
> Subject: [PATCH] cancel rfkill_poll with sync when module is exiting
> 
> Re-write the patch due to there is no response from TJ.
> 
> http://marc.info/?l=linux-wireless&m=123791044313158&w=2
> Bug: #345710
> 
> When the wireless interface is active and the iwl3945 module is unloaded the
> call to ieee80211_unregister_hw() would call iwl3945_mac_stop() which would
> restart the delayed workqueue for rfkill_poll. That workqueue had already been
> cancelled so when the next work item was run (2 seconds later) the system would
> suffer a hard lock-up because the module had been unloaded by then.
> 
> This patch implements STATUS_EXIT_PENDING checks in places where the rfkill_poll
> work is scheduled, and moves the final workqueue cancellation to occur after the
> call to ieee80211_unregister_hw().
> 
> Bug discovered, experienced and fix tested on my PC.
> 
> Signed-off-by: TJ <ubuntu at tjworld.net>
> Signed-off-by: Huaxu Wan <huaxu.wan at linux.intel.com>
> ---
>  drivers/net/wireless/iwlwifi/iwl3945-base.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/net/wireless/iwlwifi/iwl3945-base.c b/drivers/net/wireless/iwlwifi/iwl3945-base.c
> index bb92db2..08c2a9d 100644
> --- a/drivers/net/wireless/iwlwifi/iwl3945-base.c
> +++ b/drivers/net/wireless/iwlwifi/iwl3945-base.c
> @@ -8166,7 +8166,6 @@ static void __devexit iwl3945_pci_remove(struct pci_dev *pdev)
>  	sysfs_remove_group(&pdev->dev.kobj, &iwl3945_attribute_group);
>  
>  	iwl3945_rfkill_unregister(priv);
> -	cancel_delayed_work(&priv->rfkill_poll);
>  	iwl3945_dealloc_ucode_pci(priv);
>  
>  	if (priv->rxq.bd)
> @@ -8181,6 +8180,7 @@ static void __devexit iwl3945_pci_remove(struct pci_dev *pdev)
>  
>  	/*netif_stop_queue(dev); */
>  	flush_workqueue(priv->workqueue);
> +	cancel_delayed_work_sync(&priv->rfkill_poll);
>  
>  	/* ieee80211_unregister_hw calls iwl3945_mac_stop, which flushes
>  	 * priv->workqueue... so we can't take down the workqueue

ACK

-- 
Tim Gardner tim.gardner at canonical.com