[PATCH 4.4 104/134] mac80211_hwsim: enforce PS_MANUAL_POLL to be set after PS_ENABLED

From: Greg Kroah-Hartman
Date: Mon Mar 19 2018 - 16:13:40 EST


4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Adiel Aloni <adiel.aloni@xxxxxxxxx>


[ Upstream commit e16ea4bb516bc21ea2202f2107718b29218bea59 ]

Enforce using PS_MANUAL_POLL in ps hwsim debugfs to trigger a poll,
only if PS_ENABLED was set before.
This is required due to commit c9491367b759 ("mac80211: always update the
PM state of a peer on MGMT / DATA frames") that enforces the ap to
check only mgmt/data frames ps bit, and then update station's power save
accordingly.
When sending only ps-poll (control frame) the ap will not be aware that
the station entered power save.
Setting ps enable before triggering ps_poll, will send NDP with PM bit
enabled first.

Signed-off-by: Adiel Aloni <adiel.aloni@xxxxxxxxx>
Signed-off-by: Luca Coelho <luciano.coelho@xxxxxxxxx>
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/wireless/mac80211_hwsim.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)

--- a/drivers/net/wireless/mac80211_hwsim.c
+++ b/drivers/net/wireless/mac80211_hwsim.c
@@ -699,16 +699,21 @@ static int hwsim_fops_ps_write(void *dat
val != PS_MANUAL_POLL)
return -EINVAL;

- old_ps = data->ps;
- data->ps = val;
-
- local_bh_disable();
if (val == PS_MANUAL_POLL) {
+ if (data->ps != PS_ENABLED)
+ return -EINVAL;
+ local_bh_disable();
ieee80211_iterate_active_interfaces_atomic(
data->hw, IEEE80211_IFACE_ITER_NORMAL,
hwsim_send_ps_poll, data);
- data->ps_poll_pending = true;
- } else if (old_ps == PS_DISABLED && val != PS_DISABLED) {
+ local_bh_enable();
+ return 0;
+ }
+ old_ps = data->ps;
+ data->ps = val;
+
+ local_bh_disable();
+ if (old_ps == PS_DISABLED && val != PS_DISABLED) {
ieee80211_iterate_active_interfaces_atomic(
data->hw, IEEE80211_IFACE_ITER_NORMAL,
hwsim_send_nullfunc_ps, data);