wusb: whci-hcd shouldn't do ASL/PZL updates while channel is inactive

ASL/PZL updates while the WUSB channel is inactive (i.e., the PZL and
ASL are stopped) may not complete.  This causes hangs when removing the
whci-hcd module if a device is still connected (removing the device
does an endpoint_disable which results in an ASL update to remove the
qset).

If the WUSB channel is inactive the update can simply be skipped as the
WHC doesn't care about the state of the ASL/PZL.

Signed-off-by: David Vrabel <david.vrabel@csr.com>

1 files changed, 27 insertions, 10 deletions

diff --git a/drivers/usb/wusbcore/mmc.c b/drivers/usb/wusbcore/mmc.c
index 5463ecebafd..3b52161e6e9 100644
--- a/drivers/usb/wusbcore/mmc.c
+++ b/drivers/usb/wusbcore/mmc.c
@@ -159,6 +159,27 @@ found:
 }
 EXPORT_SYMBOL_GPL(wusbhc_mmcie_rm);
 
+static int wusbhc_mmc_start(struct wusbhc *wusbhc)
+{
+	int ret;
+
+	mutex_lock(&wusbhc->mutex);
+	ret = wusbhc->start(wusbhc);
+	if (ret >= 0)
+		wusbhc->active = 1;
+	mutex_unlock(&wusbhc->mutex);
+
+	return ret;
+}
+
+static void wusbhc_mmc_stop(struct wusbhc *wusbhc)
+{
+	mutex_lock(&wusbhc->mutex);
+	wusbhc->active = 0;
+	wusbhc->stop(wusbhc, WUSB_CHANNEL_STOP_DELAY_MS);
+	mutex_unlock(&wusbhc->mutex);
+}
+
 /*
  * wusbhc_start - start transmitting MMCs and accepting connections
  * @wusbhc: the HC to start
@@ -198,12 +219,12 @@ int wusbhc_start(struct wusbhc *wusbhc)
 		dev_err(dev, "Cannot set DNTS parameters: %d\n", result);
 		goto error_set_num_dnts;
 	}
-	result = wusbhc->start(wusbhc);
+	result = wusbhc_mmc_start(wusbhc);
 	if (result < 0) {
 		dev_err(dev, "error starting wusbch: %d\n", result);
 		goto error_wusbhc_start;
 	}
-	wusbhc->active = 1;
+
 	return 0;
 
 error_wusbhc_start:
@@ -225,15 +246,11 @@ error_rsv_establish:
  */
 void wusbhc_stop(struct wusbhc *wusbhc)
 {
-	if (wusbhc->active) {
-		wusbhc->active = 0;
-		wusbhc->stop(wusbhc, WUSB_CHANNEL_STOP_DELAY_MS);
-		wusbhc_sec_stop(wusbhc);
-		wusbhc_devconnect_stop(wusbhc);
-		wusbhc_rsv_terminate(wusbhc);
-	}
+	wusbhc_mmc_stop(wusbhc);
+	wusbhc_sec_stop(wusbhc);
+	wusbhc_devconnect_stop(wusbhc);
+	wusbhc_rsv_terminate(wusbhc);
 }
-EXPORT_SYMBOL_GPL(wusbhc_stop);
 
 /*
  * Set/reset/update a new CHID