USB: convert usb_hcd bitfields into atomic flags

This patch (as1393) converts several of the single-bit fields in
struct usb_hcd to atomic flags.  This is for safety's sake; not all
CPUs can update bitfield values atomically, and these flags are used
in multiple contexts.

The flag fields that are set only during registration or removal can
remain as they are, since non-atomic accesses at those times will not
cause any problems.

(Strictly speaking, the authorized_default flag should become atomic
as well.  I didn't bother with it because it gets changed only via
sysfs.  It can be done later, if anyone wants.)

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/usbip/vhci_hcd.c

@@ -215,7 +215,7 @@ static int vhci_hub_status(struct usb_hcd *hcd, char *buf)
 	vhci = hcd_to_vhci(hcd);
 
 	spin_lock_irqsave(&vhci->lock, flags);
-	if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)) {
+	if (!HCD_HW_ACCESSIBLE(hcd)) {
 		usbip_dbg_vhci_rh("hw accessible flag in on?\n");
 		goto done;
 	}
@@ -269,7 +269,7 @@ static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 
 	u32 prev_port_status[VHCI_NPORTS];
 
-	if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags))
+	if (!HCD_HW_ACCESSIBLE(hcd))
 		return -ETIMEDOUT;
 
 	/*
@@ -1041,7 +1041,7 @@ static int vhci_bus_resume(struct usb_hcd *hcd)
 	dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
 
 	spin_lock_irq(&vhci->lock);
-	if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)) {
+	if (!HCD_HW_ACCESSIBLE(hcd)) {
 		rc = -ESHUTDOWN;
 	} else {
 		/* vhci->rh_state = DUMMY_RH_RUNNING;

drivers/usb/c67x00/c67x00-hcd.c

@@ -264,7 +264,7 @@ static void c67x00_hcd_irq(struct c67x00_sie *sie, u16 int_status, u16 msg)
 	if (unlikely(hcd->state == HC_STATE_HALT))
 		return;
 
-	if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags))
+	if (!HCD_HW_ACCESSIBLE(hcd))
 		return;
 
 	/* Handle Start of frame events */
@@ -282,7 +282,7 @@ static int c67x00_hcd_start(struct usb_hcd *hcd)
 {
 	hcd->uses_new_polling = 1;
 	hcd->state = HC_STATE_RUNNING;
-	hcd->poll_rh = 1;
+	set_bit(HCD_FLAG_POLL_RH, &hcd->flags);
 
 	return 0;
 }

drivers/usb/core/hcd.c

@@ -679,7 +679,7 @@ void usb_hcd_poll_rh_status(struct usb_hcd *hcd)
 		spin_lock_irqsave(&hcd_root_hub_lock, flags);
 		urb = hcd->status_urb;
 		if (urb) {
-			hcd->poll_pending = 0;
+			clear_bit(HCD_FLAG_POLL_PENDING, &hcd->flags);
 			hcd->status_urb = NULL;
 			urb->actual_length = length;
 			memcpy(urb->transfer_buffer, buffer, length);
@@ -690,7 +690,7 @@ void usb_hcd_poll_rh_status(struct usb_hcd *hcd)
 			spin_lock(&hcd_root_hub_lock);
 		} else {
 			length = 0;
-			hcd->poll_pending = 1;
+			set_bit(HCD_FLAG_POLL_PENDING, &hcd->flags);
 		}
 		spin_unlock_irqrestore(&hcd_root_hub_lock, flags);
 	}
@@ -699,7 +699,7 @@ void usb_hcd_poll_rh_status(struct usb_hcd *hcd)
 	 * exceed that limit if HZ is 100. The math is more clunky than
 	 * maybe expected, this is to make sure that all timers for USB devices
 	 * fire at the same time to give the CPU a break inbetween */
-	if (hcd->uses_new_polling ? hcd->poll_rh :
+	if (hcd->uses_new_polling ? HCD_POLL_RH(hcd) :
 			(length == 0 && hcd->status_urb != NULL))
 		mod_timer (&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4));
 }
@@ -736,7 +736,7 @@ static int rh_queue_status (struct usb_hcd *hcd, struct urb *urb)
 		mod_timer(&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4));
 
 	/* If a status change has already occurred, report it ASAP */
-	else if (hcd->poll_pending)
+	else if (HCD_POLL_PENDING(hcd))
 		mod_timer(&hcd->rh_timer, jiffies);
 	retval = 0;
  done:
@@ -1150,8 +1150,7 @@ int usb_hcd_check_unlink_urb(struct usb_hcd *hcd, struct urb *urb,
 	 * finish unlinking the initial failed usb_set_address()
 	 * or device descriptor fetch.
 	 */
-	if (!test_bit(HCD_FLAG_SAW_IRQ, &hcd->flags) &&
-			!is_root_hub(urb->dev)) {
+	if (!HCD_SAW_IRQ(hcd) && !is_root_hub(urb->dev)) {
 		dev_warn(hcd->self.controller, "Unlink after no-IRQ?  "
 			"Controller is probably using the wrong IRQ.\n");
 		set_bit(HCD_FLAG_SAW_IRQ, &hcd->flags);
@@ -2063,8 +2062,7 @@ irqreturn_t usb_hcd_irq (int irq, void *__hcd)
 	 */
 	local_irq_save(flags);
 
-	if (unlikely(hcd->state == HC_STATE_HALT ||
-		     !test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags))) {
+	if (unlikely(hcd->state == HC_STATE_HALT || !HCD_HW_ACCESSIBLE(hcd))) {
 		rc = IRQ_NONE;
 	} else if (hcd->driver->irq(hcd) == IRQ_NONE) {
 		rc = IRQ_NONE;
@@ -2098,7 +2096,7 @@ void usb_hc_died (struct usb_hcd *hcd)
 
 	spin_lock_irqsave (&hcd_root_hub_lock, flags);
 	if (hcd->rh_registered) {
-		hcd->poll_rh = 0;
+		clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
 
 		/* make khubd clean up old urbs and devices */
 		usb_set_device_state (hcd->self.root_hub,
@@ -2301,7 +2299,7 @@ int usb_add_hcd(struct usb_hcd *hcd,
 		       retval);
 		goto error_create_attr_group;
 	}
-	if (hcd->uses_new_polling && hcd->poll_rh)
+	if (hcd->uses_new_polling && HCD_POLL_RH(hcd))
 		usb_hcd_poll_rh_status(hcd);
 	return retval;
 
@@ -2320,11 +2318,11 @@ error_create_attr_group:
 	mutex_unlock(&usb_bus_list_lock);
 err_register_root_hub:
 	hcd->rh_pollable = 0;
-	hcd->poll_rh = 0;
+	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
 	del_timer_sync(&hcd->rh_timer);
 	hcd->driver->stop(hcd);
 	hcd->state = HC_STATE_HALT;
-	hcd->poll_rh = 0;
+	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
 	del_timer_sync(&hcd->rh_timer);
 err_hcd_driver_start:
 	if (hcd->irq >= 0)
@@ -2380,14 +2378,14 @@ void usb_remove_hcd(struct usb_hcd *hcd)
 	 * the hub_status_data() callback.
 	 */
 	hcd->rh_pollable = 0;
-	hcd->poll_rh = 0;
+	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
 	del_timer_sync(&hcd->rh_timer);
 
 	hcd->driver->stop(hcd);
 	hcd->state = HC_STATE_HALT;
 
 	/* In case the HCD restarted the timer, stop it again. */
-	hcd->poll_rh = 0;
+	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
 	del_timer_sync(&hcd->rh_timer);
 
 	if (hcd->irq >= 0)

drivers/usb/gadget/dummy_hcd.c

@@ -1542,7 +1542,7 @@ static int dummy_hub_status (struct usb_hcd *hcd, char *buf)
 	dum = hcd_to_dummy (hcd);
 
 	spin_lock_irqsave (&dum->lock, flags);
-	if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags))
+	if (!HCD_HW_ACCESSIBLE(hcd))
 		goto done;
 
 	if (dum->resuming && time_after_eq (jiffies, dum->re_timeout)) {
@@ -1588,7 +1588,7 @@ static int dummy_hub_control (
 	int		retval = 0;
 	unsigned long	flags;
 
-	if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags))
+	if (!HCD_HW_ACCESSIBLE(hcd))
 		return -ETIMEDOUT;
 
 	dum = hcd_to_dummy (hcd);
@@ -1739,7 +1739,7 @@ static int dummy_bus_resume (struct usb_hcd *hcd)
 	dev_dbg (&hcd->self.root_hub->dev, "%s\n", __func__);
 
 	spin_lock_irq (&dum->lock);
-	if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)) {
+	if (!HCD_HW_ACCESSIBLE(hcd)) {
 		rc = -ESHUTDOWN;
 	} else {
 		dum->rh_state = DUMMY_RH_RUNNING;

drivers/usb/host/ehci-dbg.c

@@ -712,7 +712,7 @@ static ssize_t fill_registers_buffer(struct debug_buffer *buf)
 
 	spin_lock_irqsave (&ehci->lock, flags);
 
-	if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)) {
+	if (!HCD_HW_ACCESSIBLE(hcd)) {
 		size = scnprintf (next, size,
 			"bus %s, device %s\n"
 			"%s\n"

drivers/usb/host/ehci-hcd.c

@@ -642,7 +642,6 @@ static int ehci_run (struct usb_hcd *hcd)
 	u32			hcc_params;
 
 	hcd->uses_new_polling = 1;
-	hcd->poll_rh = 0;
 
 	/* EHCI spec section 4.1 */
 	if ((retval = ehci_reset(ehci)) != 0) {

drivers/usb/host/ehci-hub.c

@@ -316,7 +316,7 @@ static int ehci_bus_resume (struct usb_hcd *hcd)
 	if (time_before (jiffies, ehci->next_statechange))
 		msleep(5);
 	spin_lock_irq (&ehci->lock);
-	if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)) {
+	if (!HCD_HW_ACCESSIBLE(hcd)) {
 		spin_unlock_irq(&ehci->lock);
 		return -ESHUTDOWN;
 	}

drivers/usb/host/ehci-q.c

@@ -1126,8 +1126,7 @@ submit_async (
 #endif
 
 	spin_lock_irqsave (&ehci->lock, flags);
-	if (unlikely(!test_bit(HCD_FLAG_HW_ACCESSIBLE,
-			       &ehci_to_hcd(ehci)->flags))) {
+	if (unlikely(!HCD_HW_ACCESSIBLE(ehci_to_hcd(ehci)))) {
 		rc = -ESHUTDOWN;
 		goto done;
 	}

drivers/usb/host/ehci-sched.c

@@ -880,8 +880,7 @@ static int intr_submit (
 
 	spin_lock_irqsave (&ehci->lock, flags);
 
-	if (unlikely(!test_bit(HCD_FLAG_HW_ACCESSIBLE,
-			&ehci_to_hcd(ehci)->flags))) {
+	if (unlikely(!HCD_HW_ACCESSIBLE(ehci_to_hcd(ehci)))) {
 		status = -ESHUTDOWN;
 		goto done_not_linked;
 	}
@@ -1815,8 +1814,7 @@ static int itd_submit (struct ehci_hcd *ehci, struct urb *urb,
 
 	/* schedule ... need to lock */
 	spin_lock_irqsave (&ehci->lock, flags);
-	if (unlikely(!test_bit(HCD_FLAG_HW_ACCESSIBLE,
-			       &ehci_to_hcd(ehci)->flags))) {
+	if (unlikely(!HCD_HW_ACCESSIBLE(ehci_to_hcd(ehci)))) {
 		status = -ESHUTDOWN;
 		goto done_not_linked;
 	}
@@ -2201,8 +2199,7 @@ static int sitd_submit (struct ehci_hcd *ehci, struct urb *urb,
 
 	/* schedule ... need to lock */
 	spin_lock_irqsave (&ehci->lock, flags);
-	if (unlikely(!test_bit(HCD_FLAG_HW_ACCESSIBLE,
-			       &ehci_to_hcd(ehci)->flags))) {
+	if (unlikely(!HCD_HW_ACCESSIBLE(ehci_to_hcd(ehci)))) {
 		status = -ESHUTDOWN;
 		goto done_not_linked;
 	}

drivers/usb/host/hwa-hc.c

@@ -159,7 +159,7 @@ static int hwahc_op_start(struct usb_hcd *usb_hcd)
 		goto error_set_cluster_id;
 
 	usb_hcd->uses_new_polling = 1;
-	usb_hcd->poll_rh = 1;
+	set_bit(HCD_FLAG_POLL_RH, &usb_hcd->flags);
 	usb_hcd->state = HC_STATE_RUNNING;
 	result = 0;
 out:
@@ -776,7 +776,7 @@ static int hwahc_probe(struct usb_interface *usb_iface,
 		goto error_alloc;
 	}
 	usb_hcd->wireless = 1;
-	usb_hcd->flags |= HCD_FLAG_SAW_IRQ;
+	set_bit(HCD_FLAG_SAW_IRQ, &usb_hcd->flags);
 	wusbhc = usb_hcd_to_wusbhc(usb_hcd);
 	hwahc = container_of(wusbhc, struct hwahc, wusbhc);
 	hwahc_init(hwahc);

drivers/usb/host/isp1760-hcd.c

@@ -482,7 +482,6 @@ static int isp1760_run(struct usb_hcd *hcd)
 	u32 chipid;
 
 	hcd->uses_new_polling = 1;
-	hcd->poll_rh = 0;
 
 	hcd->state = HC_STATE_RUNNING;
 	isp1760_enable_interrupts(hcd);
@@ -1450,7 +1449,7 @@ static int isp1760_prepare_enqueue(struct isp1760_hcd *priv, struct urb *urb,
 	epnum = urb->ep->desc.bEndpointAddress;
 
 	spin_lock_irqsave(&priv->lock, flags);
-	if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &priv_to_hcd(priv)->flags)) {
+	if (!HCD_HW_ACCESSIBLE(priv_to_hcd(priv))) {
 		rc = -ESHUTDOWN;
 		goto done;
 	}

drivers/usb/host/ohci-dbg.c

@@ -645,7 +645,7 @@ static ssize_t fill_registers_buffer(struct debug_buffer *buf)
 		hcd->product_desc,
 		hcd_name);
 
-	if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)) {
+	if (!HCD_HW_ACCESSIBLE(hcd)) {
 		size -= scnprintf (next, size,
 			"SUSPENDED (no register access)\n");
 		goto done;
@@ -687,7 +687,7 @@ static ssize_t fill_registers_buffer(struct debug_buffer *buf)
 	next += temp;
 
 	temp = scnprintf (next, size, "hub poll timer %s\n",
-			ohci_to_hcd(ohci)->poll_rh ? "ON" : "off");
+			HCD_POLL_RH(ohci_to_hcd(ohci)) ? "ON" : "off");
 	size -= temp;
 	next += temp;
 

drivers/usb/host/ohci-hcd.c

@@ -212,7 +212,7 @@ static int ohci_urb_enqueue (
 	spin_lock_irqsave (&ohci->lock, flags);
 
 	/* don't submit to a dead HC */
-	if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)) {
+	if (!HCD_HW_ACCESSIBLE(hcd)) {
 		retval = -ENODEV;
 		goto fail;
 	}
@@ -685,7 +685,7 @@ retry:
 	}
 
 	/* use rhsc irqs after khubd is fully initialized */
-	hcd->poll_rh = 1;
+	set_bit(HCD_FLAG_POLL_RH, &hcd->flags);
 	hcd->uses_new_polling = 1;
 
 	/* start controller operations */
@@ -822,7 +822,7 @@ static irqreturn_t ohci_irq (struct usb_hcd *hcd)
 	else if (ints & OHCI_INTR_RD) {
 		ohci_vdbg(ohci, "resume detect\n");
 		ohci_writel(ohci, OHCI_INTR_RD, &regs->intrstatus);
-		hcd->poll_rh = 1;
+		set_bit(HCD_FLAG_POLL_RH, &hcd->flags);
 		if (ohci->autostop) {
 			spin_lock (&ohci->lock);
 			ohci_rh_resume (ohci);

drivers/usb/host/ohci-hub.c

@@ -284,7 +284,7 @@ static int ohci_bus_suspend (struct usb_hcd *hcd)
 
 	spin_lock_irq (&ohci->lock);
 
-	if (unlikely(!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)))
+	if (unlikely(!HCD_HW_ACCESSIBLE(hcd)))
 		rc = -ESHUTDOWN;
 	else
 		rc = ohci_rh_suspend (ohci, 0);
@@ -302,7 +302,7 @@ static int ohci_bus_resume (struct usb_hcd *hcd)
 
 	spin_lock_irq (&ohci->lock);
 
-	if (unlikely(!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)))
+	if (unlikely(!HCD_HW_ACCESSIBLE(hcd)))
 		rc = -ESHUTDOWN;
 	else
 		rc = ohci_rh_resume (ohci);
@@ -489,7 +489,7 @@ ohci_hub_status_data (struct usb_hcd *hcd, char *buf)
 	unsigned long	flags;
 
 	spin_lock_irqsave (&ohci->lock, flags);
-	if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags))
+	if (!HCD_HW_ACCESSIBLE(hcd))
 		goto done;
 
 	/* undocumented erratum seen on at least rev D */
@@ -533,8 +533,12 @@ ohci_hub_status_data (struct usb_hcd *hcd, char *buf)
 		}
 	}
 
-	hcd->poll_rh = ohci_root_hub_state_changes(ohci, changed,
-			any_connected, rhsc_status);
+	if (ohci_root_hub_state_changes(ohci, changed,
+			any_connected, rhsc_status))
+		set_bit(HCD_FLAG_POLL_RH, &hcd->flags);
+	else
+		clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
+
 
 done:
 	spin_unlock_irqrestore (&ohci->lock, flags);
@@ -701,7 +705,7 @@ static int ohci_hub_control (
 	u32		temp;
 	int		retval = 0;
 
-	if (unlikely(!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)))
+	if (unlikely(!HCD_HW_ACCESSIBLE(hcd)))
 		return -ESHUTDOWN;
 
 	switch (typeReq) {

drivers/usb/host/oxu210hp-hcd.c

@@ -1641,8 +1641,7 @@ static int submit_async(struct oxu_hcd	*oxu, struct urb *urb,
 #endif
 
 	spin_lock_irqsave(&oxu->lock, flags);
-	if (unlikely(!test_bit(HCD_FLAG_HW_ACCESSIBLE,
-			       &oxu_to_hcd(oxu)->flags))) {
+	if (unlikely(!HCD_HW_ACCESSIBLE(oxu_to_hcd(oxu)))) {
 		rc = -ESHUTDOWN;
 		goto done;
 	}
@@ -2209,8 +2208,7 @@ static int intr_submit(struct oxu_hcd *oxu, struct urb *urb,
 
 	spin_lock_irqsave(&oxu->lock, flags);
 
-	if (unlikely(!test_bit(HCD_FLAG_HW_ACCESSIBLE,
-			       &oxu_to_hcd(oxu)->flags))) {
+	if (unlikely(!HCD_HW_ACCESSIBLE(oxu_to_hcd(oxu)))) {
 		status = -ESHUTDOWN;
 		goto done;
 	}
@@ -2715,7 +2713,6 @@ static int oxu_run(struct usb_hcd *hcd)
 	u32 temp, hcc_params;
 
 	hcd->uses_new_polling = 1;
-	hcd->poll_rh = 0;
 
 	/* EHCI spec section 4.1 */
 	retval = ehci_reset(oxu);

drivers/usb/host/uhci-hcd.c

@@ -140,7 +140,7 @@ static void finish_reset(struct uhci_hcd *uhci)
 	uhci->rh_state = UHCI_RH_RESET;
 	uhci->is_stopped = UHCI_IS_STOPPED;
 	uhci_to_hcd(uhci)->state = HC_STATE_HALT;
-	uhci_to_hcd(uhci)->poll_rh = 0;
+	clear_bit(HCD_FLAG_POLL_RH, &uhci_to_hcd(uhci)->flags);
 
 	uhci->dead = 0;		/* Full reset resurrects the controller */
 }
@@ -344,7 +344,10 @@ __acquires(uhci->lock)
 	/* If interrupts don't work and remote wakeup is enabled then
 	 * the suspended root hub needs to be polled.
 	 */
-	uhci_to_hcd(uhci)->poll_rh = (!int_enable && wakeup_enable);
+	if (!int_enable && wakeup_enable)
+		set_bit(HCD_FLAG_POLL_RH, &uhci_to_hcd(uhci)->flags);
+	else
+		clear_bit(HCD_FLAG_POLL_RH, &uhci_to_hcd(uhci)->flags);
 
 	uhci_scan_schedule(uhci);
 	uhci_fsbr_off(uhci);
@@ -363,7 +366,7 @@ static void start_rh(struct uhci_hcd *uhci)
 			uhci->io_addr + USBINTR);
 	mb();
 	uhci->rh_state = UHCI_RH_RUNNING;
-	uhci_to_hcd(uhci)->poll_rh = 1;
+	set_bit(HCD_FLAG_POLL_RH, &uhci_to_hcd(uhci)->flags);
 }
 
 static void wakeup_rh(struct uhci_hcd *uhci)
@@ -733,7 +736,7 @@ static void uhci_stop(struct usb_hcd *hcd)
 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
 
 	spin_lock_irq(&uhci->lock);
-	if (test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags) && !uhci->dead)
+	if (HCD_HW_ACCESSIBLE(hcd) && !uhci->dead)
 		uhci_hc_died(uhci);
 	uhci_scan_schedule(uhci);
 	spin_unlock_irq(&uhci->lock);
@@ -750,7 +753,7 @@ static int uhci_rh_suspend(struct usb_hcd *hcd)
 	int rc = 0;
 
 	spin_lock_irq(&uhci->lock);
-	if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags))
+	if (!HCD_HW_ACCESSIBLE(hcd))
 		rc = -ESHUTDOWN;
 	else if (uhci->dead)
 		;		/* Dead controllers tell no tales */
@@ -777,7 +780,7 @@ static int uhci_rh_resume(struct usb_hcd *hcd)
 	int rc = 0;
 
 	spin_lock_irq(&uhci->lock);
-	if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags))
+	if (!HCD_HW_ACCESSIBLE(hcd))
 		rc = -ESHUTDOWN;
 	else if (!uhci->dead)
 		wakeup_rh(uhci);
@@ -793,7 +796,7 @@ static int uhci_pci_suspend(struct usb_hcd *hcd)
 	dev_dbg(uhci_dev(uhci), "%s\n", __func__);
 
 	spin_lock_irq(&uhci->lock);
-	if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags) || uhci->dead)
+	if (!HCD_HW_ACCESSIBLE(hcd) || uhci->dead)
 		goto done_okay;		/* Already suspended or dead */
 
 	if (uhci->rh_state > UHCI_RH_SUSPENDED) {
@@ -807,7 +810,7 @@ static int uhci_pci_suspend(struct usb_hcd *hcd)
 	 */
 	pci_write_config_word(to_pci_dev(uhci_dev(uhci)), USBLEGSUP, 0);
 	mb();
-	hcd->poll_rh = 0;
+	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
 
 	/* FIXME: Enable non-PME# remote wakeup? */
 
@@ -860,7 +863,7 @@ static int uhci_pci_resume(struct usb_hcd *hcd, bool hibernated)
 	 * the suspended root hub needs to be polled.
 	 */
 	if (!uhci->RD_enable && hcd->self.root_hub->do_remote_wakeup) {
-		hcd->poll_rh = 1;
+		set_bit(HCD_FLAG_POLL_RH, &hcd->flags);
 		usb_hcd_poll_rh_status(hcd);
 	}
 	return 0;

drivers/usb/host/uhci-hub.c

@@ -190,7 +190,7 @@ static int uhci_hub_status_data(struct usb_hcd *hcd, char *buf)
 	spin_lock_irqsave(&uhci->lock, flags);
 
 	uhci_scan_schedule(uhci);
-	if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags) || uhci->dead)
+	if (!HCD_HW_ACCESSIBLE(hcd) || uhci->dead)
 		goto done;
 	uhci_check_ports(uhci);
 
@@ -246,7 +246,7 @@ static int uhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 	u16 wPortChange, wPortStatus;
 	unsigned long flags;
 
-	if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags) || uhci->dead)
+	if (!HCD_HW_ACCESSIBLE(hcd) || uhci->dead)
 		return -ETIMEDOUT;
 
 	spin_lock_irqsave(&uhci->lock, flags);

drivers/usb/host/whci/hcd.c

@@ -68,7 +68,7 @@ static int whc_start(struct usb_hcd *usb_hcd)
 	whc_write_wusbcmd(whc, WUSBCMD_RUN, WUSBCMD_RUN);
 
 	usb_hcd->uses_new_polling = 1;
-	usb_hcd->poll_rh = 1;
+	set_bit(HCD_FLAG_POLL_RH, &usb_hcd->flags);
 	usb_hcd->state = HC_STATE_RUNNING;
 
 out:

drivers/usb/host/xhci.c

@@ -427,7 +427,6 @@ int xhci_run(struct usb_hcd *hcd)
 	void (*doorbell)(struct xhci_hcd *) = NULL;
 
 	hcd->uses_new_polling = 1;
-	hcd->poll_rh = 0;
 
 	xhci_dbg(xhci, "xhci_run\n");
 #if 0	/* FIXME: MSI not setup yet */
@@ -733,7 +732,7 @@ int xhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flags)
 		ret = -EINVAL;
 		goto exit;
 	}
-	if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)) {
+	if (!HCD_HW_ACCESSIBLE(hcd)) {
 		if (!in_interrupt())
 			xhci_dbg(xhci, "urb submitted during PCI suspend\n");
 		ret = -ESHUTDOWN;

drivers/usb/musb/musb_virthub.c

@@ -244,7 +244,7 @@ int musb_hub_control(
 
 	spin_lock_irqsave(&musb->lock, flags);
 
-	if (unlikely(!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags))) {
+	if (unlikely(!HCD_HW_ACCESSIBLE(hcd))) {
 		spin_unlock_irqrestore(&musb->lock, flags);
 		return -ESHUTDOWN;
 	}

include/linux/usb/hcd.h

@@ -89,19 +89,31 @@ struct usb_hcd {
 	 */
 	const struct hc_driver	*driver;	/* hw-specific hooks */
 
-	/* Flags that need to be manipulated atomically */
+	/* Flags that need to be manipulated atomically because they can
+	 * change while the host controller is running.  Always use
+	 * set_bit() or clear_bit() to change their values.
+	 */
 	unsigned long		flags;
-#define HCD_FLAG_HW_ACCESSIBLE	0x00000001
-#define HCD_FLAG_SAW_IRQ	0x00000002
+#define HCD_FLAG_HW_ACCESSIBLE		0	/* at full power */
+#define HCD_FLAG_SAW_IRQ		1
+#define HCD_FLAG_POLL_RH		2	/* poll for rh status? */
+#define HCD_FLAG_POLL_PENDING		3	/* status has changed? */
+
+	/* The flags can be tested using these macros; they are likely to
+	 * be slightly faster than test_bit().
+	 */
+#define HCD_HW_ACCESSIBLE(hcd)	((hcd)->flags & (1U << HCD_FLAG_HW_ACCESSIBLE))
+#define HCD_SAW_IRQ(hcd)	((hcd)->flags & (1U << HCD_FLAG_SAW_IRQ))
+#define HCD_POLL_RH(hcd)	((hcd)->flags & (1U << HCD_FLAG_POLL_RH))
+#define HCD_POLL_PENDING(hcd)	((hcd)->flags & (1U << HCD_FLAG_POLL_PENDING))
 
+	/* Flags that get set only during HCD registration or removal. */
 	unsigned		rh_registered:1;/* is root hub registered? */
 	unsigned		rh_pollable:1;	/* may we poll the root hub? */
 
 	/* The next flag is a stopgap, to be removed when all the HCDs
 	 * support the new root-hub polling mechanism. */
 	unsigned		uses_new_polling:1;
-	unsigned		poll_rh:1;	/* poll for rh status? */
-	unsigned		poll_pending:1;	/* status has changed? */
 	unsigned		wireless:1;	/* Wireless USB HCD */
 	unsigned		authorized_default:1;
 	unsigned		has_tt:1;	/* Integrated TT in root hub */