[PATCH 50/55] staging: wfx: rewrite wfx_hw_scan()

Jérôme Pouiller
2019-12-16T17:09:03Z

Scan requests from mac80211 must be splitted in a few hardware requests
(it is necessary to split channels with active scan and channels with
passive scan). Current code schedules a work_struct for each hardware
request and one delayed_work to handle scan timeout.

It is far simpler to run send all the hardware requests synchronously
and replace delayed_work with a simple wait_for_completion_timeout().

Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
---
drivers/staging/wfx/hif_rx.c | 2 +-
drivers/staging/wfx/scan.c | 225 ++++++++++-------------------------
drivers/staging/wfx/scan.h | 23 +---
drivers/staging/wfx/sta.c | 39 ++----
drivers/staging/wfx/wfx.h | 4 +-
5 files changed, 81 insertions(+), 212 deletions(-)

diff --git a/drivers/staging/wfx/hif_rx.c b/drivers/staging/wfx/hif_rx.c
index 8a3ccdc60b7d..408967a4c457 100644
--- a/drivers/staging/wfx/hif_rx.c
+++ b/drivers/staging/wfx/hif_rx.c
@@ -206,7 +206,7 @@ static int hif_scan_complete_indication(struct wfx_dev *wdev,
const struct hif_ind_scan_cmpl *body = buf;

WARN_ON(!wvif);
- wfx_scan_complete_cb(wvif, body);
+ wfx_scan_complete(wvif, body);

return 0;
}
diff --git a/drivers/staging/wfx/scan.c b/drivers/staging/wfx/scan.c
index c82c04ff5d06..b73e61e8da46 100644
--- a/drivers/staging/wfx/scan.c
+++ b/drivers/staging/wfx/scan.c
@@ -22,33 +22,6 @@ static void __ieee80211_scan_completed_compat(struct ieee80211_hw *hw,
ieee80211_scan_completed(hw, &info);
}

-static void wfx_scan_restart_delayed(struct wfx_vif *wvif)
-{
- if (wvif->delayed_unjoin) {
- wvif->delayed_unjoin = false;
- if (!schedule_work(&wvif->unjoin_work))
- wfx_tx_unlock(wvif->wdev);
- } else if (wvif->delayed_link_loss) {
- wvif->delayed_link_loss = 0;
- wfx_cqm_bssloss_sm(wvif, 1, 0, 0);
- }
-}
-
-static int wfx_scan_start(struct wfx_vif *wvif,
- int chan_start_idx, int chan_num)
-{
- int tmo;
-
- if (wvif->state == WFX_STATE_PRE_STA)
- return -EBUSY;
-
- atomic_set(&wvif->scan.in_progress, 1);
-
- tmo = hif_scan(wvif, wvif->scan.req, chan_start_idx, chan_num);
- schedule_delayed_work(&wvif->scan.timeout, tmo);
- return 0;
-}
-
static int update_probe_tmpl(struct wfx_vif *wvif,
struct cfg80211_scan_request *req)
{
@@ -65,153 +38,81 @@ static int update_probe_tmpl(struct wfx_vif *wvif,
return 0;
}

-int wfx_hw_scan(struct ieee80211_hw *hw,
- struct ieee80211_vif *vif,
- struct ieee80211_scan_request *hw_req)
+static int send_scan_req(struct wfx_vif *wvif,
+ struct cfg80211_scan_request *req, int start_idx)
+{
+ int i, ret, timeout;
+ struct ieee80211_channel *ch_start, *ch_cur;
+
+ for (i = start_idx; i < req->n_channels; i++) {
+ ch_start = req->channels[start_idx];
+ ch_cur = req->channels[i];
+ WARN(ch_cur->band != NL80211_BAND_2GHZ, "band not supported");
+ if (ch_cur->max_power != ch_start->max_power)
+ break;
+ if ((ch_cur->flags ^ ch_start->flags) & IEEE80211_CHAN_NO_IR)
+ break;
+ }
+ wfx_tx_lock_flush(wvif->wdev);
+ reinit_completion(&wvif->scan_complete);
+ ret = hif_scan(wvif, req, start_idx, i - start_idx);
+ if (ret < 0)
+ return ret;
+ timeout = ret;
+ ret = wait_for_completion_timeout(&wvif->scan_complete, timeout);
+ if (req->channels[start_idx]->max_power != wvif->wdev->output_power)
+ hif_set_output_power(wvif, wvif->wdev->output_power * 10);
+ wfx_tx_unlock(wvif->wdev);
+ if (!ret) {
+ dev_notice(wvif->wdev->dev, "scan timeout\n");
+ hif_stop_scan(wvif);
+ return -ETIMEDOUT;
+ }
+ return i - start_idx;
+}
+
+int wfx_hw_scan(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
+ struct ieee80211_scan_request *hw_req)
{
struct wfx_dev *wdev = hw->priv;
struct wfx_vif *wvif = (struct wfx_vif *) vif->drv_priv;
- struct cfg80211_scan_request *req = &hw_req->req;
- int i, ret;
+ int chan_cur, ret;

- if (!wvif)
- return -EINVAL;
+ WARN_ON(hw_req->req.n_channels > HIF_API_MAX_NB_CHANNELS);

- if (wvif->state == WFX_STATE_AP)
+ if (vif->type == NL80211_IFTYPE_AP)
return -EOPNOTSUPP;

- if (req->n_ssids == 1 && !req->ssids[0].ssid_len)
- req->n_ssids = 0;
-
- if (req->n_ssids > HIF_API_MAX_NB_SSIDS)
- return -EINVAL;
+ if (wvif->state == WFX_STATE_PRE_STA)
+ return -EBUSY;

+ mutex_lock(&wvif->scan_lock);
mutex_lock(&wdev->conf_mutex);
-
- ret = update_probe_tmpl(wvif, req);
- if (ret)
- goto failed;
-
- ret = wfx_fwd_probe_req(wvif, true);
- if (ret)
- goto failed;
-
- wfx_tx_lock_flush(wdev);
-
- WARN(wvif->scan.req, "unexpected concurrent scan");
- wvif->scan.req = req;
- wvif->scan.n_ssids = 0;
- wvif->scan.status = 0;
- wvif->scan.begin = &req->channels[0];
- wvif->scan.curr = wvif->scan.begin;
- wvif->scan.end = &req->channels[req->n_channels];
- wvif->scan.output_power = wdev->output_power;
-
- for (i = 0; i < req->n_ssids; ++i) {
- struct hif_ssid_def *dst = &wvif->scan.ssids[wvif->scan.n_ssids];
-
- memcpy(&dst->ssid[0], req->ssids[i].ssid, sizeof(dst->ssid));
- dst->ssid_length = req->ssids[i].ssid_len;
- ++wvif->scan.n_ssids;
- }
- schedule_work(&wvif->scan.work);
-
-failed:
+ update_probe_tmpl(wvif, &hw_req->req);
+ wfx_fwd_probe_req(wvif, true);
+ chan_cur = 0;
+ do {
+ ret = send_scan_req(wvif, &hw_req->req, chan_cur);
+ if (ret > 0)
+ chan_cur += ret;
+ } while (ret > 0 && chan_cur < hw_req->req.n_channels);
+ __ieee80211_scan_completed_compat(hw, ret < 0);
mutex_unlock(&wdev->conf_mutex);
- return ret;
-}
-
-void wfx_scan_work(struct work_struct *work)
-{
- struct wfx_vif *wvif = container_of(work, struct wfx_vif, scan.work);
- struct ieee80211_channel **it;
- struct ieee80211_channel *first;
- int i;
-
- down(&wvif->scan.lock);
- mutex_lock(&wvif->wdev->conf_mutex);
-
-
- if (!wvif->scan.req || wvif->scan.curr == wvif->scan.end) {
- if (wvif->scan.output_power != wvif->wdev->output_power)
- hif_set_output_power(wvif,
- wvif->wdev->output_power * 10);
-
- if (wvif->scan.status < 0)
- dev_warn(wvif->wdev->dev, "scan failed\n");
- else if (wvif->scan.req)
- dev_dbg(wvif->wdev->dev, "scan completed\n");
- else
- dev_dbg(wvif->wdev->dev, "scan canceled\n");
-
- wvif->scan.req = NULL;
- wfx_scan_restart_delayed(wvif);
- wfx_tx_unlock(wvif->wdev);
- mutex_unlock(&wvif->wdev->conf_mutex);
- __ieee80211_scan_completed_compat(wvif->wdev->hw,
- wvif->scan.status ? 1 : 0);
- up(&wvif->scan.lock);
- return;
- }
- first = *wvif->scan.curr;
-
- for (it = wvif->scan.curr + 1, i = 1;
- it != wvif->scan.end && i < HIF_API_MAX_NB_CHANNELS;
- ++it, ++i) {
- if ((*it)->band != first->band)
- break;
- if (((*it)->flags ^ first->flags) &
- IEEE80211_CHAN_NO_IR)
- break;
- if (!(first->flags & IEEE80211_CHAN_NO_IR) &&
- (*it)->max_power != first->max_power)
- break;
- }
- if (!(first->flags & IEEE80211_CHAN_NO_IR) &&
- wvif->scan.output_power != first->max_power) {
- wvif->scan.output_power = first->max_power;
- hif_set_output_power(wvif, wvif->scan.output_power * 10);
+ mutex_unlock(&wvif->scan_lock);
+ if (wvif->delayed_unjoin) {
+ wvif->delayed_unjoin = false;
+ wfx_tx_lock(wdev);
+ if (!schedule_work(&wvif->unjoin_work))
+ wfx_tx_unlock(wdev);
+ } else if (wvif->delayed_link_loss) {
+ wvif->delayed_link_loss = false;
+ wfx_cqm_bssloss_sm(wvif, 1, 0, 0);
}
- wvif->scan.status = wfx_scan_start(wvif,
- wvif->scan.curr - wvif->scan.begin,
- it - wvif->scan.curr);
- if (wvif->scan.status)
- goto fail;
- wvif->scan.curr = it;
- mutex_unlock(&wvif->wdev->conf_mutex);
- return;
-
-fail:
- wvif->scan.curr = wvif->scan.end;
- mutex_unlock(&wvif->wdev->conf_mutex);
- up(&wvif->scan.lock);
- schedule_work(&wvif->scan.work);
+ return 0;
}

-void wfx_scan_complete_cb(struct wfx_vif *wvif,
- const struct hif_ind_scan_cmpl *arg)
+void wfx_scan_complete(struct wfx_vif *wvif,
+ const struct hif_ind_scan_cmpl *arg)
{
- if (cancel_delayed_work_sync(&wvif->scan.timeout) > 0) {
- wvif->scan.status = 1;
- schedule_work(&wvif->scan.timeout.work);
- }
-}
-
-void wfx_scan_timeout(struct work_struct *work)
-{
- struct wfx_vif *wvif = container_of(work, struct wfx_vif,
- scan.timeout.work);
-
- if (atomic_xchg(&wvif->scan.in_progress, 0)) {
- if (wvif->scan.status > 0) {
- wvif->scan.status = 0;
- } else if (!wvif->scan.status) {
- dev_warn(wvif->wdev->dev, "timeout waiting for scan complete notification\n");
- wvif->scan.status = -ETIMEDOUT;
- wvif->scan.curr = wvif->scan.end;
- hif_stop_scan(wvif);
- }
- up(&wvif->scan.lock);
- wfx_scan_work(&wvif->scan.work);
- }
+ complete(&wvif->scan_complete);
}
diff --git a/drivers/staging/wfx/scan.h b/drivers/staging/wfx/scan.h
index e71e5f0f522e..03bc6c7e562d 100644
--- a/drivers/staging/wfx/scan.h
+++ b/drivers/staging/wfx/scan.h
@@ -8,8 +8,6 @@
#ifndef WFX_SCAN_H
#define WFX_SCAN_H

-#include <linux/semaphore.h>
-#include <linux/workqueue.h>
#include <net/mac80211.h>

#include "hif_api_cmd.h"
@@ -17,26 +15,9 @@
struct wfx_dev;
struct wfx_vif;

-struct wfx_scan {
- struct semaphore lock;
- struct work_struct work;
- struct delayed_work timeout;
- struct cfg80211_scan_request *req;
- struct ieee80211_channel **begin;
- struct ieee80211_channel **curr;
- struct ieee80211_channel **end;
- struct hif_ssid_def ssids[HIF_API_MAX_NB_SSIDS];
- int output_power;
- int n_ssids;
- int status;
- atomic_t in_progress;
-};
-
int wfx_hw_scan(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
struct ieee80211_scan_request *req);
-void wfx_scan_work(struct work_struct *work);
-void wfx_scan_timeout(struct work_struct *work);
-void wfx_scan_complete_cb(struct wfx_vif *wvif,
- const struct hif_ind_scan_cmpl *arg);
+void wfx_scan_complete(struct wfx_vif *wvif,
+ const struct hif_ind_scan_cmpl *ind);

#endif /* WFX_SCAN_H */
diff --git a/drivers/staging/wfx/sta.c b/drivers/staging/wfx/sta.c
index ba3e81fd477b..16f5db873275 100644
--- a/drivers/staging/wfx/sta.c
+++ b/drivers/staging/wfx/sta.c
@@ -277,13 +277,13 @@ void wfx_configure_filter(struct ieee80211_hw *hw,
*total_flags &= FIF_OTHER_BSS | FIF_FCSFAIL | FIF_PROBE_REQ;

while ((wvif = wvif_iterate(wdev, wvif)) != NULL) {
- down(&wvif->scan.lock);
+ mutex_lock(&wvif->scan_lock);
wvif->filter_bssid = (*total_flags &
(FIF_OTHER_BSS | FIF_PROBE_REQ)) ? 0 : 1;
wvif->disable_beacon_filter = !(*total_flags & FIF_PROBE_REQ);
wfx_fwd_probe_req(wvif, true);
wfx_update_filtering(wvif);
- up(&wvif->scan.lock);
+ mutex_unlock(&wvif->scan_lock);
}
}

@@ -433,9 +433,9 @@ static void wfx_event_handler_work(struct work_struct *work)
switch (event->evt.event_id) {
case HIF_EVENT_IND_BSSLOST:
cancel_work_sync(&wvif->unjoin_work);
- if (!down_trylock(&wvif->scan.lock)) {
+ if (mutex_trylock(&wvif->scan_lock)) {
wfx_cqm_bssloss_sm(wvif, 1, 0, 0);
- up(&wvif->scan.lock);
+ mutex_unlock(&wvif->scan_lock);
} else {
/* Scan is in progress. Delay reporting.
* Scan complete will trigger bss_loss_work
@@ -501,7 +501,7 @@ static void wfx_do_unjoin(struct wfx_vif *wvif)
{
mutex_lock(&wvif->wdev->conf_mutex);

- if (atomic_read(&wvif->scan.in_progress)) {
+ if (!mutex_trylock(&wvif->scan_lock)) {
if (wvif->delayed_unjoin)
dev_dbg(wvif->wdev->dev,
"delayed unjoin is already scheduled\n");
@@ -509,6 +509,7 @@ static void wfx_do_unjoin(struct wfx_vif *wvif)
wvif->delayed_unjoin = true;
goto done;
}
+ mutex_unlock(&wvif->scan_lock);

wvif->delayed_link_loss = false;

@@ -613,14 +614,6 @@ static void wfx_do_join(struct wfx_vif *wvif)

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

- /* Under the conf lock: check scan status and
- * bail out if it is in progress.
- */
- if (atomic_read(&wvif->scan.in_progress)) {
- wfx_tx_unlock(wvif->wdev);
- goto done_put;
- }
-
/* Sanity check basic rates */
if (!join.basic_rate_set)
join.basic_rate_set = 7;
@@ -684,7 +677,6 @@ static void wfx_do_join(struct wfx_vif *wvif)
}
wfx_update_filtering(wvif);

-done_put:
mutex_unlock(&wvif->wdev->conf_mutex);
if (bss)
cfg80211_put_bss(wvif->wdev->hw->wiphy, bss);
@@ -1346,7 +1338,7 @@ int wfx_config(struct ieee80211_hw *hw, u32 changed)
return 0;
}

- down(&wvif->scan.lock);
+ mutex_lock(&wvif->scan_lock);
mutex_lock(&wdev->conf_mutex);
if (changed & IEEE80211_CONF_CHANGE_POWER) {
wdev->output_power = conf->power_level;
@@ -1361,7 +1353,7 @@ int wfx_config(struct ieee80211_hw *hw, u32 changed)
}

mutex_unlock(&wdev->conf_mutex);
- up(&wvif->scan.lock);
+ mutex_unlock(&wvif->scan_lock);
return ret;
}

@@ -1419,10 +1411,6 @@ int wfx_add_interface(struct ieee80211_hw *hw, struct ieee80211_vif *vif)
wvif->wep_default_key_id = -1;
INIT_WORK(&wvif->wep_key_work, wfx_wep_key_work);

- sema_init(&wvif->scan.lock, 1);
- INIT_WORK(&wvif->scan.work, wfx_scan_work);
- INIT_DELAYED_WORK(&wvif->scan.timeout, wfx_scan_timeout);
-
spin_lock_init(&wvif->event_queue_lock);
INIT_LIST_HEAD(&wvif->event_queue);
INIT_WORK(&wvif->event_handler_work, wfx_event_handler_work);
@@ -1435,8 +1423,11 @@ int wfx_add_interface(struct ieee80211_hw *hw, struct ieee80211_vif *vif)
INIT_WORK(&wvif->bss_params_work, wfx_bss_params_work);
INIT_WORK(&wvif->set_cts_work, wfx_set_cts_work);
INIT_WORK(&wvif->unjoin_work, wfx_unjoin_work);
-
INIT_WORK(&wvif->tx_policy_upload_work, wfx_tx_policy_upload_work);
+
+ mutex_init(&wvif->scan_lock);
+ init_completion(&wvif->scan_complete);
+
mutex_unlock(&wdev->conf_mutex);

hif_set_macaddr(wvif, vif->addr);
@@ -1462,10 +1453,6 @@ void wfx_remove_interface(struct ieee80211_hw *hw,
struct wfx_vif *wvif = (struct wfx_vif *) vif->drv_priv;
int i;

- // If scan is in progress, stop it
- while (down_trylock(&wvif->scan.lock))
- schedule();
- up(&wvif->scan.lock);
wait_for_completion_timeout(&wvif->set_pm_mode_complete, msecs_to_jiffies(300));

mutex_lock(&wdev->conf_mutex);
@@ -1505,8 +1492,6 @@ void wfx_remove_interface(struct ieee80211_hw *hw,
/* FIXME: In add to reset MAC address, try to reset interface */
hif_set_macaddr(wvif, NULL);

- cancel_delayed_work_sync(&wvif->scan.timeout);
-
wfx_cqm_bssloss_sm(wvif, 0, 0, 0);
cancel_work_sync(&wvif->unjoin_work);
cancel_delayed_work_sync(&wvif->link_id_gc_work);
diff --git a/drivers/staging/wfx/wfx.h b/drivers/staging/wfx/wfx.h
index 35f5ddc2eeb3..3356d0cbf7af 100644
--- a/drivers/staging/wfx/wfx.h
+++ b/drivers/staging/wfx/wfx.h
@@ -125,7 +125,9 @@ struct wfx_vif {
bool delayed_unjoin;
struct work_struct unjoin_work;

- struct wfx_scan scan;
+ /* avoid some operations in parallel with scan */
+ struct mutex scan_lock;
+ struct completion scan_complete;

struct completion set_pm_mode_complete;

--
2.20.1