Re: [BUG] 3.10 regression: hang on suspend

From: Stanislaw Gruszka
Date: Mon Jul 22 2013 - 07:19:47 EST


On Fri, Jul 19, 2013 at 08:46:54PM +0200, Ortwin Glück wrote:
> On 07/19/2013 02:08 PM, Stanislaw Gruszka wrote:
> >I'm attaching patch, which should prevent crash (but not fix the issue,
> >just workaround it), plese apply it. If it make suspend work, please then
> >reload iwlwifi module with debug=0x3 option, suspend/resume machine and
> >provide dmesg output after that.
>
>
> Here the requested dmesg. Please note that two different WARN_ONs
> trigger here directly after each other.
>
> To me it looks like iwlagn_mac_remove_interface() is called twice,
> but I am not familiar with the code.

We remove interface that we do not add in the driver. I think I found
reason of that - I removed below code in bad commit:

list_for_each_entry(sdata, &local->interfaces, list) {
[snip]
- switch (sdata->vif.type) {
- case NL80211_IFTYPE_AP_VLAN:
- case NL80211_IFTYPE_MONITOR:
- /* skip these */
- continue;

Attached patch should correct that. Please test if it fixes the
crash.

Thanks
Stanislaw

diff --git a/net/mac80211/pm.c b/net/mac80211/pm.c
index 7fc5d0d..3401262 100644
--- a/net/mac80211/pm.c
+++ b/net/mac80211/pm.c
@@ -99,10 +99,13 @@ int __ieee80211_suspend(struct ieee80211_hw *hw, struct cfg80211_wowlan *wowlan)
}
mutex_unlock(&local->sta_mtx);

- /* remove all interfaces */
+ /* remove all interfaces that were created in the driver */
list_for_each_entry(sdata, &local->interfaces, list) {
- if (!ieee80211_sdata_running(sdata))
+ if (!ieee80211_sdata_running(sdata) ||
+ sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
+ sdata->vif.type == NL80211_IFTYPE_MONITOR)
continue;
+
drv_remove_interface(local, sdata);
}