linux-stable/net/mac80211/pm.c
Johannes Berg a05829a722 cfg80211: avoid holding the RTNL when calling the driver
Currently, _everything_ in cfg80211 holds the RTNL, and if you
have a slow USB device (or a few) you can get some bad lock
contention on that.

Fix that by re-adding a mutex to each wiphy/rdev as we had at
some point, so we have locking for the wireless_dev lists and
all the other things in there, and also so that drivers still
don't have to worry too much about it (they still won't get
parallel calls for a single device).

Then, we can restrict the RTNL to a few cases where we add or
remove interfaces and really need the added protection. Some
of the global list management still also uses the RTNL, since
we need to have it anyway for netdev management, but we only
hold the RTNL for very short periods of time here.

Link: https://lore.kernel.org/r/20210122161942.81df9f5e047a.I4a8e1a60b18863ea8c5e6d3a0faeafb2d45b2f40@changeid
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> [marvell driver issues]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2021-01-26 11:55:50 +01:00

197 lines
5.1 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Portions
* Copyright (C) 2020-2021 Intel Corporation
*/
#include <net/mac80211.h>
#include <net/rtnetlink.h>
#include "ieee80211_i.h"
#include "mesh.h"
#include "driver-ops.h"
#include "led.h"
static void ieee80211_sched_scan_cancel(struct ieee80211_local *local)
{
if (ieee80211_request_sched_scan_stop(local))
return;
cfg80211_sched_scan_stopped_locked(local->hw.wiphy, 0);
}
int __ieee80211_suspend(struct ieee80211_hw *hw, struct cfg80211_wowlan *wowlan)
{
struct ieee80211_local *local = hw_to_local(hw);
struct ieee80211_sub_if_data *sdata;
struct sta_info *sta;
if (!local->open_count)
goto suspend;
ieee80211_scan_cancel(local);
ieee80211_dfs_cac_cancel(local);
ieee80211_roc_purge(local, NULL);
ieee80211_del_virtual_monitor(local);
if (ieee80211_hw_check(hw, AMPDU_AGGREGATION) &&
!(wowlan && wowlan->any)) {
mutex_lock(&local->sta_mtx);
list_for_each_entry(sta, &local->sta_list, list) {
set_sta_flag(sta, WLAN_STA_BLOCK_BA);
ieee80211_sta_tear_down_BA_sessions(
sta, AGG_STOP_LOCAL_REQUEST);
}
mutex_unlock(&local->sta_mtx);
}
/* keep sched_scan only in case of 'any' trigger */
if (!(wowlan && wowlan->any))
ieee80211_sched_scan_cancel(local);
ieee80211_stop_queues_by_reason(hw,
IEEE80211_MAX_QUEUE_MAP,
IEEE80211_QUEUE_STOP_REASON_SUSPEND,
false);
/* flush out all packets */
synchronize_net();
ieee80211_flush_queues(local, NULL, true);
local->quiescing = true;
/* make quiescing visible to timers everywhere */
mb();
flush_workqueue(local->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);
local->wowlan = wowlan;
if (local->wowlan) {
int err;
/* Drivers don't expect to suspend while some operations like
* authenticating or associating are in progress. It doesn't
* make sense anyway to accept that, since the authentication
* or association would never finish since the driver can't do
* that on its own.
* Thus, clean up in-progress auth/assoc first.
*/
list_for_each_entry(sdata, &local->interfaces, list) {
if (!ieee80211_sdata_running(sdata))
continue;
if (sdata->vif.type != NL80211_IFTYPE_STATION)
continue;
ieee80211_mgd_quiesce(sdata);
/* If suspended during TX in progress, and wowlan
* is enabled (connection will be active) there
* can be a race where the driver is put out
* of power-save due to TX and during suspend
* dynamic_ps_timer is cancelled and TX packet
* is flushed, leaving the driver in ACTIVE even
* after resuming until dynamic_ps_timer puts
* driver back in DOZE.
*/
if (sdata->u.mgd.associated &&
sdata->u.mgd.powersave &&
!(local->hw.conf.flags & IEEE80211_CONF_PS)) {
local->hw.conf.flags |= IEEE80211_CONF_PS;
ieee80211_hw_config(local,
IEEE80211_CONF_CHANGE_PS);
}
}
err = drv_suspend(local, wowlan);
if (err < 0) {
local->quiescing = false;
local->wowlan = false;
if (ieee80211_hw_check(hw, AMPDU_AGGREGATION)) {
mutex_lock(&local->sta_mtx);
list_for_each_entry(sta,
&local->sta_list, list) {
clear_sta_flag(sta, WLAN_STA_BLOCK_BA);
}
mutex_unlock(&local->sta_mtx);
}
ieee80211_wake_queues_by_reason(hw,
IEEE80211_MAX_QUEUE_MAP,
IEEE80211_QUEUE_STOP_REASON_SUSPEND,
false);
return err;
} else if (err > 0) {
WARN_ON(err != 1);
/* cfg80211 will call back into mac80211 to disconnect
* all interfaces, allow that to proceed properly
*/
ieee80211_wake_queues_by_reason(hw,
IEEE80211_MAX_QUEUE_MAP,
IEEE80211_QUEUE_STOP_REASON_SUSPEND,
false);
return err;
} else {
goto suspend;
}
}
/* remove all interfaces that were created in the driver */
list_for_each_entry(sdata, &local->interfaces, list) {
if (!ieee80211_sdata_running(sdata))
continue;
switch (sdata->vif.type) {
case NL80211_IFTYPE_AP_VLAN:
case NL80211_IFTYPE_MONITOR:
continue;
case NL80211_IFTYPE_STATION:
ieee80211_mgd_quiesce(sdata);
break;
default:
break;
}
flush_delayed_work(&sdata->dec_tailroom_needed_wk);
drv_remove_interface(local, sdata);
}
/*
* We disconnected on all interfaces before suspend, all channel
* contexts should be released.
*/
WARN_ON(!list_empty(&local->chanctx_list));
/* stop hardware - this must stop RX */
ieee80211_stop_device(local);
suspend:
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.
*/
void ieee80211_report_wowlan_wakeup(struct ieee80211_vif *vif,
struct cfg80211_wowlan_wakeup *wakeup,
gfp_t gfp)
{
struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
cfg80211_report_wowlan_wakeup(&sdata->wdev, wakeup, gfp);
}
EXPORT_SYMBOL(ieee80211_report_wowlan_wakeup);