staging: wfx: wait for SCAN_CMPL after a SCAN_STOP

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>
Link: https://lore.kernel.org/r/20210913130203.1903622-5-Jerome.Pouiller@silabs.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/wfx/scan.c b/drivers/staging/wfx/scan.c
index fb47c7cddf2f1960ab2d886d3f447cd3e20b35fa..1e03b130049bc187d07d2deacefbe90ae10fe869 100644 (file)
--- 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;
 }
 
 /*