diff --git a/drivers/usb/host/whci/asl.c b/drivers/usb/host/whci/asl.c
index 4d7078e..ba99a7a 100644
--- a/drivers/usb/host/whci/asl.c
+++ b/drivers/usb/host/whci/asl.c
@@ -179,11 +179,26 @@
 		      1000, "stop ASL");
 }
 
+/**
+ * asl_update - request an ASL update and wait for the hardware to be synced
+ * @whc: the WHCI HC
+ * @wusbcmd: WUSBCMD value to start the update.
+ *
+ * If the WUSB HC is inactive (i.e., the ASL is stopped) then the
+ * update must be skipped as the hardware may not respond to update
+ * requests.
+ */
 void asl_update(struct whc *whc, uint32_t wusbcmd)
 {
-	whc_write_wusbcmd(whc, wusbcmd, wusbcmd);
-	wait_event(whc->async_list_wq,
-		   (le_readl(whc->base + WUSBCMD) & WUSBCMD_ASYNC_UPDATED) == 0);
+	struct wusbhc *wusbhc = &whc->wusbhc;
+
+	mutex_lock(&wusbhc->mutex);
+	if (wusbhc->active) {
+		whc_write_wusbcmd(whc, wusbcmd, wusbcmd);
+		wait_event(whc->async_list_wq,
+			   (le_readl(whc->base + WUSBCMD) & WUSBCMD_ASYNC_UPDATED) == 0);
+	}
+	mutex_unlock(&wusbhc->mutex);
 }
 
 /**
diff --git a/drivers/usb/host/whci/pzl.c b/drivers/usb/host/whci/pzl.c
index 8d62df0..34d3a0a 100644
--- a/drivers/usb/host/whci/pzl.c
+++ b/drivers/usb/host/whci/pzl.c
@@ -195,11 +195,26 @@
 		      1000, "stop PZL");
 }
 
+/**
+ * pzl_update - request a PZL update and wait for the hardware to be synced
+ * @whc: the WHCI HC
+ * @wusbcmd: WUSBCMD value to start the update.
+ *
+ * If the WUSB HC is inactive (i.e., the PZL is stopped) then the
+ * update must be skipped as the hardware may not respond to update
+ * requests.
+ */
 void pzl_update(struct whc *whc, uint32_t wusbcmd)
 {
-	whc_write_wusbcmd(whc, wusbcmd, wusbcmd);
-	wait_event(whc->periodic_list_wq,
-		   (le_readl(whc->base + WUSBCMD) & WUSBCMD_PERIODIC_UPDATED) == 0);
+	struct wusbhc *wusbhc = &whc->wusbhc;
+
+	mutex_lock(&wusbhc->mutex);
+	if (wusbhc->active) {
+		whc_write_wusbcmd(whc, wusbcmd, wusbcmd);
+		wait_event(whc->periodic_list_wq,
+			   (le_readl(whc->base + WUSBCMD) & WUSBCMD_PERIODIC_UPDATED) == 0);
+	}
+	mutex_unlock(&wusbhc->mutex);
 }
 
 static void update_pzl_hw_view(struct whc *whc)
diff --git a/drivers/usb/wusbcore/devconnect.c b/drivers/usb/wusbcore/devconnect.c
index 08a1ec9..26cbc89 100644
--- a/drivers/usb/wusbcore/devconnect.c
+++ b/drivers/usb/wusbcore/devconnect.c
@@ -484,21 +484,15 @@
  */
 static void wusbhc_keep_alive_run(struct work_struct *ws)
 {
-	struct delayed_work *dw =
-		container_of(ws, struct delayed_work, work);
-	struct wusbhc *wusbhc =
-		container_of(dw, struct wusbhc, keep_alive_timer);
+	struct delayed_work *dw = container_of(ws, struct delayed_work, work);
+	struct wusbhc *wusbhc =	container_of(dw, struct wusbhc, keep_alive_timer);
 
-	d_fnstart(5, wusbhc->dev, "(wusbhc %p)\n", wusbhc);
-	if (wusbhc->active) {
-		mutex_lock(&wusbhc->mutex);
-		__wusbhc_keep_alive(wusbhc);
-		mutex_unlock(&wusbhc->mutex);
-		queue_delayed_work(wusbd, &wusbhc->keep_alive_timer,
-				   (wusbhc->trust_timeout * CONFIG_HZ)/1000/2);
-	}
-	d_fnend(5, wusbhc->dev, "(wusbhc %p) = void\n", wusbhc);
-	return;
+	mutex_lock(&wusbhc->mutex);
+	__wusbhc_keep_alive(wusbhc);
+	mutex_unlock(&wusbhc->mutex);
+
+	queue_delayed_work(wusbd, &wusbhc->keep_alive_timer,
+			   msecs_to_jiffies(wusbhc->trust_timeout / 2));
 }
 
 /*
diff --git a/drivers/usb/wusbcore/mmc.c b/drivers/usb/wusbcore/mmc.c
index 5463ece..3b52161 100644
--- a/drivers/usb/wusbcore/mmc.c
+++ b/drivers/usb/wusbcore/mmc.c
@@ -159,6 +159,27 @@
 }
 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 @@
 		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 @@
  */
 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