[PATCH v3 04/32] staging: wfx: wait for SCAN_CMPL after a SCAN_STOP

[Jerome Pouiller <Jerome.Pouiller@silabs.com>]

From: Jérôme Pouiller <jerome.pouiller@silabs.com>

When the device has finished a scan request, it send a scan complete
("SCAN_COMPL") indication. It is also possible to abort a scan request
with a "SCAN_STOP" message. A SCAN_COMPL is also send in this case.

The driver limits the delay to make a scan request. A timeout happens
almost never but is theoretically possible. Currently, if it happens
the driver does not wait for the SCAN_COMPL. Then, when the driver
starts the next scan request, the device may return -EBUSY (scan
requests often occur back-to-back).

This patch give a chance to the device to send a SCAN_COMPL after a scan
timeout.

Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
---
 drivers/staging/wfx/scan.c | 24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/drivers/staging/wfx/scan.c b/drivers/staging/wfx/scan.c
index fb47c7cddf2f..1e03b130049b 100644
--- a/drivers/staging/wfx/scan.c
+++ b/drivers/staging/wfx/scan.c
@@ -58,23 +58,31 @@ static int send_scan_req(struct wfx_vif *wvif,
 	reinit_completion(&wvif->scan_complete);
 	ret = hif_scan(wvif, req, start_idx, i - start_idx, &timeout);
 	if (ret) {
-		wfx_tx_unlock(wvif->wdev);
-		return -EIO;
+		ret = -EIO;
+		goto err_scan_start;
 	}
 	ret = wait_for_completion_timeout(&wvif->scan_complete, timeout);
-	if (req->channels[start_idx]->max_power != wvif->vif->bss_conf.txpower)
-		hif_set_output_power(wvif, wvif->vif->bss_conf.txpower);
-	wfx_tx_unlock(wvif->wdev);
 	if (!ret) {
 		dev_notice(wvif->wdev->dev, "scan timeout\n");
 		hif_stop_scan(wvif);
-		return -ETIMEDOUT;
+		ret = wait_for_completion_timeout(&wvif->scan_complete, 1 * HZ);
+		if (!ret)
+			dev_err(wvif->wdev->dev, "scan didn't stop\n");
+		ret = -ETIMEDOUT;
+		goto err_timeout;
 	}
 	if (wvif->scan_abort) {
 		dev_notice(wvif->wdev->dev, "scan abort\n");
-		return -ECONNABORTED;
+		ret = -ECONNABORTED;
+		goto err_timeout;
 	}
-	return i - start_idx;
+	ret = i - start_idx;
+err_timeout:
+	if (req->channels[start_idx]->max_power != wvif->vif->bss_conf.txpower)
+		hif_set_output_power(wvif, wvif->vif->bss_conf.txpower);
+err_scan_start:
+	wfx_tx_unlock(wvif->wdev);
+	return ret;
 }
 
 /*
-- 
2.33.0