The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x fbc1cc6973099f45e4c30b86f12b4435c7cb7d24 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025110947-demote-preppy-79bf@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From fbc1cc6973099f45e4c30b86f12b4435c7cb7d24 Mon Sep 17 00:00:00 2001 From: Benjamin Berg benjamin.berg@intel.com Date: Tue, 28 Oct 2025 12:58:40 +0200 Subject: [PATCH] wifi: mac80211: use wiphy_hrtimer_work for csa.switch_work

The work item may be scheduled relatively far in the future. As the event happens at a specific point in time, the normal timer accuracy is not sufficient in that case.

Switch to use wiphy_hrtimer_work so that the accuracy is sufficient. To make this work, use the same clock to store the timestamp.

CC: stable@vger.kernel.org Fixes: ec3252bff7b6 ("wifi: mac80211: use wiphy work for channel switch") Signed-off-by: Benjamin Berg benjamin.berg@intel.com Reviewed-by: Johannes Berg johannes.berg@intel.com Signed-off-by: Miri Korenblit miriam.rachel.korenblit@intel.com Link: https://patch.msgid.link/20251028125710.68258c7e4ac4.I4ff2b2cdffbbf858bf5f08... Signed-off-by: Johannes Berg johannes.berg@intel.com

diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c index 57065714cf8c..7f8799fd673e 100644 --- a/net/mac80211/chan.c +++ b/net/mac80211/chan.c @@ -1290,7 +1290,7 @@ ieee80211_link_chanctx_reservation_complete(struct ieee80211_link_data *link) &link->csa.finalize_work); break; case NL80211_IFTYPE_STATION: - wiphy_delayed_work_queue(sdata->local->hw.wiphy, + wiphy_hrtimer_work_queue(sdata->local->hw.wiphy, &link->u.mgd.csa.switch_work, 0); break; case NL80211_IFTYPE_UNSPECIFIED: diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index eb38049b2252..878c3b14aeb8 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -1017,10 +1017,10 @@ struct ieee80211_link_data_managed { bool operating_11g_mode;

struct { - struct wiphy_delayed_work switch_work; + struct wiphy_hrtimer_work switch_work; struct cfg80211_chan_def ap_chandef; struct ieee80211_parsed_tpe tpe; - unsigned long time; + ktime_t time; bool waiting_bcn; bool ignored_same_chan; bool blocked_tx; diff --git a/net/mac80211/link.c b/net/mac80211/link.c index d71eabe5abf8..4a19b765ccb6 100644 --- a/net/mac80211/link.c +++ b/net/mac80211/link.c @@ -472,10 +472,10 @@ static int _ieee80211_set_active_links(struct ieee80211_sub_if_data *sdata, * from there. */ if (link->conf->csa_active) - wiphy_delayed_work_queue(local->hw.wiphy, + wiphy_hrtimer_work_queue(local->hw.wiphy, &link->u.mgd.csa.switch_work, link->u.mgd.csa.time - - jiffies); + ktime_get_boottime()); }

for_each_set_bit(link_id, &add, IEEE80211_MLD_MAX_NUM_LINKS) { diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c index f95bcf84ecc2..f3138d158535 100644 --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -2594,7 +2594,7 @@ void ieee80211_chswitch_done(struct ieee80211_vif *vif, bool success, return; }

- wiphy_delayed_work_queue(sdata->local->hw.wiphy, + wiphy_hrtimer_work_queue(sdata->local->hw.wiphy, &link->u.mgd.csa.switch_work, 0); }

@@ -2753,7 +2753,8 @@ ieee80211_sta_process_chanswitch(struct ieee80211_link_data *link, .timestamp = timestamp, .device_timestamp = device_timestamp, }; - unsigned long now; + u32 csa_time_tu; + ktime_t now; int res;

lockdep_assert_wiphy(local->hw.wiphy); @@ -2983,10 +2984,9 @@ ieee80211_sta_process_chanswitch(struct ieee80211_link_data *link, csa_ie.mode);

/* we may have to handle timeout for deactivated link in software */ - now = jiffies; - link->u.mgd.csa.time = now + - TU_TO_JIFFIES((max_t(int, csa_ie.count, 1) - 1) * - link->conf->beacon_int); + now = ktime_get_boottime(); + csa_time_tu = (max_t(int, csa_ie.count, 1) - 1) * link->conf->beacon_int; + link->u.mgd.csa.time = now + us_to_ktime(ieee80211_tu_to_usec(csa_time_tu));

if (ieee80211_vif_link_active(&sdata->vif, link->link_id) && local->ops->channel_switch) { @@ -3001,7 +3001,7 @@ ieee80211_sta_process_chanswitch(struct ieee80211_link_data *link, }

/* channel switch handled in software */ - wiphy_delayed_work_queue(local->hw.wiphy, + wiphy_hrtimer_work_queue(local->hw.wiphy, &link->u.mgd.csa.switch_work, link->u.mgd.csa.time - now); return; @@ -8849,7 +8849,7 @@ void ieee80211_mgd_setup_link(struct ieee80211_link_data *link) else link->u.mgd.req_smps = IEEE80211_SMPS_OFF;

- wiphy_delayed_work_init(&link->u.mgd.csa.switch_work, + wiphy_hrtimer_work_init(&link->u.mgd.csa.switch_work, ieee80211_csa_switch_work);

ieee80211_clear_tpe(&link->conf->tpe); @@ -10064,7 +10064,7 @@ void ieee80211_mgd_stop_link(struct ieee80211_link_data *link) &link->u.mgd.request_smps_work); wiphy_work_cancel(link->sdata->local->hw.wiphy, &link->u.mgd.recalc_smps); - wiphy_delayed_work_cancel(link->sdata->local->hw.wiphy, + wiphy_hrtimer_work_cancel(link->sdata->local->hw.wiphy, &link->u.mgd.csa.switch_work); }