Re: [3.2-rc3] 100% CPU usage while in del_timer_sync from iwl3945_rs_free_sta

[Stanislaw Gruszka <sgruszka@redhat.com>]

[-- Attachment #1: Type: text/plain, Size: 280 bytes --]

On Wed, Nov 30, 2011 at 03:03:16PM +0100, Michal Hocko wrote:
> No, didn't help unfortunately...

Lets gather some more messages. Please apply attached simple patch,
recompile with:
CONFIG_MAC80211_DEBUG_MENU=y
CONFIG_MAC80211_VERBOSE_DEBUG=y
and provide dmesg.

Thanks
Stanislaw

[-- Attachment #2: mac80211_debug.patch --]
[-- Type: text/plain, Size: 887 bytes --]

diff --git a/drivers/net/wireless/iwlegacy/iwl-3945-rs.c b/drivers/net/wireless/iwlegacy/iwl-3945-rs.c
index 8faeaf2..c728f94 100644
--- a/drivers/net/wireless/iwlegacy/iwl-3945-rs.c
+++ b/drivers/net/wireless/iwlegacy/iwl-3945-rs.c
@@ -413,6 +413,7 @@ static void *iwl3945_rs_alloc_sta(void *iwl_priv, struct ieee80211_sta *sta, gfp
 	IWL_DEBUG_RATE(priv, "enter\n");
 
 	rs_sta = &psta->rs_sta;
+	printk("%s rs_sta %p\n", __func__, rs_sta);
 
 	spin_lock_init(&rs_sta->lock);
 	init_timer(&rs_sta->rate_scale_flush);
@@ -432,6 +433,10 @@ static void iwl3945_rs_free_sta(void *iwl_priv, struct ieee80211_sta *sta,
 	 * to use iwl_priv to print out debugging) since it may not be fully
 	 * initialized at this point.
 	 */
+
+	printk("%s rs_sta %p\n", __func__, rs_sta);
+	if (WARN_ON(rs_sta->rate_scale_flush.base == NULL))
+		return;
 	del_timer_sync(&rs_sta->rate_scale_flush);
 }