In order to have the pm_qos framework be callable from interrupt
context, all listeners have to also be callable in that context.
This patch schedules the update of the latency value via
ieee80211_max_network_latency() for execution on
the global workqueue (using schedule_work()).
As there was no synchronization/locking between the listener and the
caller of pm_qos_update_request before, there should be no new races
uncovered by this. Although the timing probably changes.
Signed-off-by: Florian Mickler <florian@xxxxxxxxxxx>
---
This needs some networking expertise to check the reasoning above and
judge the implementation.
net/mac80211/ieee80211_i.h | 4 +++-
net/mac80211/main.c | 5 +++--
net/mac80211/mlme.c | 20 +++++++++++++++-----
3 files changed, 21 insertions(+), 8 deletions(-)
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 1a9e2da..3d2155a 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -851,6 +851,7 @@ struct ieee80211_local {
struct work_struct dynamic_ps_disable_work;
struct timer_list dynamic_ps_timer;
struct notifier_block network_latency_notifier;
+ struct work_struct network_latency_notifier_work;
int user_power_level; /* in dBm */
int power_constr_level; /* in dBm */
@@ -994,8 +995,9 @@ ieee80211_rx_result ieee80211_sta_rx_mgmt(struct ieee80211_sub_if_data *sdata,
void ieee80211_send_pspoll(struct ieee80211_local *local,
struct ieee80211_sub_if_data *sdata);
void ieee80211_recalc_ps(struct ieee80211_local *local, s32 latency);
-int ieee80211_max_network_latency(struct notifier_block *nb,
+int ieee80211_max_network_latency_notification(struct notifier_block *nb,
unsigned long data, void *dummy);
+void ieee80211_max_network_latency(struct work_struct *w);
void ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
struct ieee80211_channel_sw_ie *sw_elem,
struct ieee80211_bss *bss,
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 22a384d..5cded3a 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -607,9 +607,10 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
rtnl_unlock();
ieee80211_led_init(local);
-
+ INIT_WORK(&local->network_latency_notifier_work,
+ ieee80211_max_network_latency);
local->network_latency_notifier.notifier_call =
- ieee80211_max_network_latency;
+ ieee80211_max_network_latency_notification;
result = pm_qos_add_notifier(PM_QOS_NETWORK_LATENCY,
&local->network_latency_notifier);
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 0839c4e..feb6134 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1953,17 +1953,27 @@ void ieee80211_mlme_notify_scan_completed(struct ieee80211_local *local)
rcu_read_unlock();
}
-int ieee80211_max_network_latency(struct notifier_block *nb,
- unsigned long data, void *dummy)
+void ieee80211_max_network_latency(struct work_struct *w)
{
- s32 latency_usec = (s32) data;
+ s32 latency_usec = (s32) atomic_long_read(&w->data);
struct ieee80211_local *local =
- container_of(nb, struct ieee80211_local,
- network_latency_notifier);
+ container_of(w, struct ieee80211_local,
+ network_latency_notifier_work);
mutex_lock(&local->iflist_mtx);
ieee80211_recalc_ps(local, latency_usec);
mutex_unlock(&local->iflist_mtx);
+}
+
+/* the notifier might be called from interrupt context */
+int ieee80211_max_network_latency_notification(struct notifier_block *nb,
+ unsigned long data, void *dummy)
+{
+ struct ieee80211_local *local =
+ container_of(nb, struct ieee80211_local,
+ network_latency_notifier);
+ atomic_long_set(&local->network_latency_notifier_work.data, data);
+ schedule_work(&local->network_latency_notifier_work);
return 0;
}
--
1.7.1
--
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