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, 3 insertions, 6 deletions

diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c
index 805ec633a652..d640346f9b56 100644
--- a/drivers/usb/host/ehci-sched.c
+++ b/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;
         }