Commit fc627dad authored by Jérôme Pouiller's avatar Jérôme Pouiller Committed by Kalle Valo
Browse files

wifi: wfx: implement wfx_remain_on_channel() 



With some conditions, the device is able to send/receive frames during
scan operation. So, it is possible to use it implement the "remain on
channel" feature. We just ask for a passive scan (without sending any
probe request) on one channel.

This architecture allows to leverage some interesting features:
  - if the device is AP, the device switches channel just after the next
    beacon and the beacons are stopped during the off-channel interval.
  - if the device is connected, it advertises it is asleep before to
    switch channel (so the AP should stop to try to send data)

Signed-off-by: default avatarJérôme Pouiller <jerome.pouiller@silabs.com>
Signed-off-by: default avatarKalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20231004172843.195332-9-jerome.pouiller@silabs.com
parent f7385a20

drivers/net/wireless/silabs/wfx/main.c

+3 −0
Original line number Diff line number Diff line
@@ -151,6 +151,8 @@ static const struct ieee80211_ops wfx_ops = { 
	.change_chanctx          = wfx_change_chanctx,

	.assign_vif_chanctx      = wfx_assign_vif_chanctx,

	.unassign_vif_chanctx    = wfx_unassign_vif_chanctx,

	.remain_on_channel       = wfx_remain_on_channel,

	.cancel_remain_on_channel = wfx_cancel_remain_on_channel,

};



bool wfx_api_older_than(struct wfx_dev *wdev, int major, int minor)
@@ -289,6 +291,7 @@ struct wfx_dev *wfx_init_common(struct device *dev, const struct wfx_platform_da 
	hw->wiphy->features |= NL80211_FEATURE_AP_SCAN;

	hw->wiphy->flags |= WIPHY_FLAG_AP_PROBE_RESP_OFFLOAD;

	hw->wiphy->flags |= WIPHY_FLAG_AP_UAPSD;

	hw->wiphy->max_remain_on_channel_duration = 5000;

	hw->wiphy->max_ap_assoc_sta = HIF_LINK_ID_MAX;

	hw->wiphy->max_scan_ssids = 2;

	hw->wiphy->max_scan_ie_len = IEEE80211_MAX_DATA_LEN;

drivers/net/wireless/silabs/wfx/scan.c

+62 −0
Original line number Diff line number Diff line
@@ -145,3 +145,65 @@ void wfx_scan_complete(struct wfx_vif *wvif, int nb_chan_done) 
	wvif->scan_nb_chan_done = nb_chan_done;

	complete(&wvif->scan_complete);

}



void wfx_remain_on_channel_work(struct work_struct *work)

{

	struct wfx_vif *wvif = container_of(work, struct wfx_vif, remain_on_channel_work);

	struct ieee80211_channel *chan = wvif->remain_on_channel_chan;

	int duration = wvif->remain_on_channel_duration;

	int ret;



	/* Hijack scan request to implement Remain-On-Channel */

	mutex_lock(&wvif->wdev->conf_mutex);

	mutex_lock(&wvif->wdev->scan_lock);

	if (wvif->join_in_progress) {

		dev_info(wvif->wdev->dev, "abort in-progress REQ_JOIN");

		wfx_reset(wvif);

	}

	wfx_tx_flush(wvif->wdev);



	reinit_completion(&wvif->scan_complete);

	ret = wfx_hif_scan_uniq(wvif, chan, duration);

	if (ret)

		goto end;

	ieee80211_ready_on_channel(wvif->wdev->hw);

	ret = wait_for_completion_timeout(&wvif->scan_complete,

					  msecs_to_jiffies(duration * 120 / 100));

	if (!ret) {

		wfx_hif_stop_scan(wvif);

		ret = wait_for_completion_timeout(&wvif->scan_complete, 1 * HZ);

		dev_dbg(wvif->wdev->dev, "roc timeout\n");

	}

	if (!ret)

		dev_err(wvif->wdev->dev, "roc didn't stop\n");

	ieee80211_remain_on_channel_expired(wvif->wdev->hw);

end:

	mutex_unlock(&wvif->wdev->scan_lock);

	mutex_unlock(&wvif->wdev->conf_mutex);

	wfx_bh_request_tx(wvif->wdev);

}



int wfx_remain_on_channel(struct ieee80211_hw *hw, struct ieee80211_vif *vif,

			  struct ieee80211_channel *chan, int duration,

			  enum ieee80211_roc_type type)

{

	struct wfx_dev *wdev = hw->priv;

	struct wfx_vif *wvif = (struct wfx_vif *)vif->drv_priv;



	if (wfx_api_older_than(wdev, 3, 10))

		return -EOPNOTSUPP;



	wvif->remain_on_channel_duration = duration;

	wvif->remain_on_channel_chan = chan;

	schedule_work(&wvif->remain_on_channel_work);

	return 0;

}



int wfx_cancel_remain_on_channel(struct ieee80211_hw *hw, struct ieee80211_vif *vif)

{

	struct wfx_vif *wvif = (struct wfx_vif *)vif->drv_priv;



	wfx_hif_stop_scan(wvif);

	flush_work(&wvif->remain_on_channel_work);

	return 0;

}

drivers/net/wireless/silabs/wfx/scan.h

+6 −0
Original line number Diff line number Diff line
@@ -19,4 +19,10 @@ int wfx_hw_scan(struct ieee80211_hw *hw, struct ieee80211_vif *vif, 
void wfx_cancel_hw_scan(struct ieee80211_hw *hw, struct ieee80211_vif *vif);

void wfx_scan_complete(struct wfx_vif *wvif, int nb_chan_done);



void wfx_remain_on_channel_work(struct work_struct *work);

int wfx_remain_on_channel(struct ieee80211_hw *hw, struct ieee80211_vif *vif,

			  struct ieee80211_channel *chan, int duration,

			  enum ieee80211_roc_type type);

int wfx_cancel_remain_on_channel(struct ieee80211_hw *hw, struct ieee80211_vif *vif);



#endif

drivers/net/wireless/silabs/wfx/sta.c

+1 −0
Original line number Diff line number Diff line
@@ -728,6 +728,7 @@ int wfx_add_interface(struct ieee80211_hw *hw, struct ieee80211_vif *vif) 


	init_completion(&wvif->scan_complete);

	INIT_WORK(&wvif->scan_work, wfx_hw_scan_work);

	INIT_WORK(&wvif->remain_on_channel_work, wfx_remain_on_channel_work);



	wfx_tx_queues_init(wvif);

	wfx_tx_policy_init(wvif);

drivers/net/wireless/silabs/wfx/wfx.h

+4 −1
Original line number Diff line number Diff line
@@ -70,6 +70,7 @@ struct wfx_vif { 


	bool                       after_dtim_tx_allowed;

	bool                       join_in_progress;

	struct completion          set_pm_mode_complete;



	struct delayed_work        beacon_loss_work;
@@ -87,7 +88,9 @@ struct wfx_vif { 
	bool                       scan_abort;

	struct ieee80211_scan_request *scan_req;



	struct completion          set_pm_mode_complete;

	struct ieee80211_channel   *remain_on_channel_chan;

	int                        remain_on_channel_duration;

	struct work_struct         remain_on_channel_work;

};



static inline struct ieee80211_vif *wvif_to_vif(struct wfx_vif *wvif)