This is a note to let you know that I've just added the patch titled mac80211: fix power saving clients handling in iwlwifi to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mac80211-fix-power-saving-clients-handling-in-iwlwifi.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Thu Oct 19 15:15:46 CEST 2017 From: Emmanuel Grumbach <emmanuel.grumbach@xxxxxxxxx> Date: Mon, 20 Feb 2017 14:24:36 +0100 Subject: mac80211: fix power saving clients handling in iwlwifi From: Emmanuel Grumbach <emmanuel.grumbach@xxxxxxxxx> [ Upstream commit d98937f4ea713d21e0fcc345919f86c877dd8d6f ] iwlwifi now supports RSS and can't let mac80211 track the PS state based on the Rx frames since they can come out of order. iwlwifi is now advertising AP_LINK_PS, and uses explicit notifications to teach mac80211 about the PS state of the stations and the PS poll / uAPSD trigger frames coming our way from the peers. Because of that, the TIM stopped being maintained in mac80211. I tried to fix this in commit c68df2e7be0c ("mac80211: allow using AP_LINK_PS with mac80211-generated TIM IE") but that was later reverted by Felix in commit 6c18a6b4e799 ("Revert "mac80211: allow using AP_LINK_PS with mac80211-generated TIM IE") since it broke drivers that do not implement set_tim. Since none of the drivers that set AP_LINK_PS have the set_tim() handler set besides iwlwifi, I can bail out in __sta_info_recalc_tim if AP_LINK_PS AND .set_tim is not implemented. Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@xxxxxxxxx> Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/mac80211/sta_info.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/mac80211/sta_info.c +++ b/net/mac80211/sta_info.c @@ -661,7 +661,7 @@ static void __sta_info_recalc_tim(struct } /* No need to do anything if the driver does all */ - if (ieee80211_hw_check(&local->hw, AP_LINK_PS)) + if (ieee80211_hw_check(&local->hw, AP_LINK_PS) && !local->ops->set_tim) return; if (sta->dead) Patches currently in stable-queue which might be from emmanuel.grumbach@xxxxxxxxx are queue-4.4/mac80211-fix-power-saving-clients-handling-in-iwlwifi.patch