staging: wfx: add a debugfs entry to force ps_timeout

In some advanced usage or debug scenarios, it could interesting to
change the value of ps_timeout or eventually to force use of PS-Poll
frames.

The wext API (used by iwconfig) provide a way to change ps_timeout.
However, this API is obsolete and it seems a little weird to use (it
seems it does apply the change, so the user have to disable then
re-enable de power save)

On side of nl80211, there is no way to change the ps_timeout.

This patch provides a file in debugfs to change the value of ps_timeout.

Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20200701150707.222985-13-Jerome.Pouiller@silabs.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/wfx/debug.c

@@ -334,6 +334,28 @@ static const struct file_operations wfx_send_hif_msg_fops = {
 	.read = wfx_send_hif_msg_read,
 };
 
+static int wfx_ps_timeout_set(void *data, u64 val)
+{
+	struct wfx_dev *wdev = (struct wfx_dev *)data;
+	struct wfx_vif *wvif;
+
+	wdev->force_ps_timeout = val;
+	wvif = NULL;
+	while ((wvif = wvif_iterate(wdev, wvif)) != NULL)
+		wfx_update_pm(wvif);
+	return 0;
+}
+
+static int wfx_ps_timeout_get(void *data, u64 *val)
+{
+	struct wfx_dev *wdev = (struct wfx_dev *)data;
+
+	*val = wdev->force_ps_timeout;
+	return 0;
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(wfx_ps_timeout_fops, wfx_ps_timeout_get, wfx_ps_timeout_set, "%lld\n");
+
 int wfx_debug_init(struct wfx_dev *wdev)
 {
 	struct dentry *d;
@@ -348,6 +370,7 @@ int wfx_debug_init(struct wfx_dev *wdev)
 			    &wfx_burn_slk_key_fops);
 	debugfs_create_file("send_hif_msg", 0600, d, wdev,
 			    &wfx_send_hif_msg_fops);
+	debugfs_create_file("ps_timeout", 0600, d, wdev, &wfx_ps_timeout_fops);
 
 	return 0;
 }

drivers/staging/wfx/main.c

@@ -352,6 +352,7 @@ struct wfx_dev *wfx_init_common(struct device *dev,
 	skb_queue_head_init(&wdev->tx_pending);
 	init_waitqueue_head(&wdev->tx_dequeue);
 	wfx_init_hif_cmd(&wdev->hif_cmd);
+	wdev->force_ps_timeout = -1;
 
 	if (devm_add_action_or_reset(dev, wfx_free_common, wdev))
 		return NULL;

drivers/staging/wfx/sta.c

@@ -217,20 +217,24 @@ static int wfx_get_ps_timeout(struct wfx_vif *wvif, bool *enable_ps)
 		// are differents.
 		if (enable_ps)
 			*enable_ps = true;
-		if (wvif->bss_not_support_ps_poll)
+		if (wvif->wdev->force_ps_timeout > -1)
+			return wvif->wdev->force_ps_timeout;
+		else if (wvif->bss_not_support_ps_poll)
 			return 30;
 		else
 			return 0;
 	}
 	if (enable_ps)
 		*enable_ps = wvif->vif->bss_conf.ps;
-	if (wvif->vif->bss_conf.assoc && wvif->vif->bss_conf.ps)
+	if (wvif->wdev->force_ps_timeout > -1)
+		return wvif->wdev->force_ps_timeout;
+	else if (wvif->vif->bss_conf.assoc && wvif->vif->bss_conf.ps)
 		return conf->dynamic_ps_timeout;
 	else
 		return -1;
 }
 
-static int wfx_update_pm(struct wfx_vif *wvif)
+int wfx_update_pm(struct wfx_vif *wvif)
 {
 	int ps_timeout;
 	bool ps;

drivers/staging/wfx/sta.h

@@ -66,6 +66,7 @@ void wfx_cooling_timeout_work(struct work_struct *work);
 void wfx_suspend_hot_dev(struct wfx_dev *wdev, enum sta_notify_cmd cmd);
 void wfx_suspend_resume_mc(struct wfx_vif *wvif, enum sta_notify_cmd cmd);
 void wfx_event_report_rssi(struct wfx_vif *wvif, u8 raw_rcpi_rssi);
+int wfx_update_pm(struct wfx_vif *wvif);
 
 // Other Helpers
 void wfx_reset(struct wfx_vif *wvif);

drivers/staging/wfx/wfx.h

@@ -59,6 +59,7 @@ struct wfx_dev {
 	struct mutex		rx_stats_lock;
 	struct hif_tx_power_loop_info tx_power_loop_info;
 	struct mutex		tx_power_loop_info_lock;
+	int			force_ps_timeout;
 };
 
 struct wfx_vif {