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>

1 files changed, 12 insertions, 9 deletions

diff --git a/drivers/usb/host/uhci-hcd.c b/drivers/usb/host/uhci-hcd.c
index d1dce21..2743ec7 100644
--- a/drivers/usb/host/uhci-hcd.c
+++ b/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;