kernel_optimize_test/net/mac80211/pm.c
Johannes Berg 89c3a8aca2 mac80211: fix suspend
Jan reported that his b43-based laptop hangs during suspend.
The problem turned out to be mac80211 asking the driver to
stop the hardware before removing interfaces, and interface
removal caused b43 to touch the hardware (while down, which
causes the hang).

This patch fixes mac80211 to do reorder these operations to
have them in the correct order -- first remove interfaces
and then stop the hardware. Some more code is necessary to
be able to do so in a race-free manner, in particular it is
necessary to not process frames received during quiescing.

Fixes http://bugzilla.kernel.org/show_bug.cgi?id=13337.

Reported-by: Jan Scholz <scholz@fias.uni-frankfurt.de>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-07-29 14:52:01 -04:00

131 lines
3.0 KiB
C

#include <net/mac80211.h>
#include <net/rtnetlink.h>
#include "ieee80211_i.h"
#include "mesh.h"
#include "driver-ops.h"
#include "led.h"
int __ieee80211_suspend(struct ieee80211_hw *hw)
{
struct ieee80211_local *local = hw_to_local(hw);
struct ieee80211_sub_if_data *sdata;
struct ieee80211_if_init_conf conf;
struct sta_info *sta;
unsigned long flags;
ieee80211_scan_cancel(local);
ieee80211_stop_queues_by_reason(hw,
IEEE80211_QUEUE_STOP_REASON_SUSPEND);
/* flush out all packets */
synchronize_net();
local->quiescing = true;
/* make quiescing visible to timers everywhere */
mb();
flush_workqueue(local->hw.workqueue);
/* Don't try to run timers while suspended. */
del_timer_sync(&local->sta_cleanup);
/*
* Note that this particular timer doesn't need to be
* restarted at resume.
*/
cancel_work_sync(&local->dynamic_ps_enable_work);
del_timer_sync(&local->dynamic_ps_timer);
/* disable keys */
list_for_each_entry(sdata, &local->interfaces, list)
ieee80211_disable_keys(sdata);
/* Tear down aggregation sessions */
rcu_read_lock();
if (hw->flags & IEEE80211_HW_AMPDU_AGGREGATION) {
list_for_each_entry_rcu(sta, &local->sta_list, list) {
set_sta_flags(sta, WLAN_STA_SUSPEND);
ieee80211_sta_tear_down_BA_sessions(sta);
}
}
rcu_read_unlock();
/* remove STAs */
spin_lock_irqsave(&local->sta_lock, flags);
list_for_each_entry(sta, &local->sta_list, list) {
if (local->ops->sta_notify) {
sdata = sta->sdata;
if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
sdata = container_of(sdata->bss,
struct ieee80211_sub_if_data,
u.ap);
drv_sta_notify(local, &sdata->vif, STA_NOTIFY_REMOVE,
&sta->sta);
}
mesh_plink_quiesce(sta);
}
spin_unlock_irqrestore(&local->sta_lock, flags);
/* remove all interfaces */
list_for_each_entry(sdata, &local->interfaces, list) {
switch(sdata->vif.type) {
case NL80211_IFTYPE_STATION:
ieee80211_sta_quiesce(sdata);
break;
case NL80211_IFTYPE_ADHOC:
ieee80211_ibss_quiesce(sdata);
break;
case NL80211_IFTYPE_MESH_POINT:
ieee80211_mesh_quiesce(sdata);
break;
case NL80211_IFTYPE_AP_VLAN:
case NL80211_IFTYPE_MONITOR:
/* don't tell driver about this */
continue;
default:
break;
}
if (!netif_running(sdata->dev))
continue;
conf.vif = &sdata->vif;
conf.type = sdata->vif.type;
conf.mac_addr = sdata->dev->dev_addr;
drv_remove_interface(local, &conf);
}
/* stop hardware - this must stop RX */
if (local->open_count) {
ieee80211_led_radio(local, false);
drv_stop(local);
}
/*
* flush again, in case driver queued work -- it
* shouldn't be doing (or cancel everything in the
* stop callback) that but better safe than sorry.
*/
flush_workqueue(local->hw.workqueue);
local->suspended = true;
/* need suspended to be visible before quiescing is false */
barrier();
local->quiescing = false;
return 0;
}
/*
* __ieee80211_resume() is a static inline which just calls
* ieee80211_reconfig(), which is also needed for hardware
* hang/firmware failure/etc. recovery.
*/