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USB: convert usb_hcd bitfields into atomic flags

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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>
This commit is contained in:
Alan Stern
2010-06-22 16:39:10 -04:00
committed by Greg Kroah-Hartman
parent 89ba85d401
commit 541c7d432f
21 changed files with 80 additions and 73 deletions
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16
drivers/usb/host/ohci-hub.c
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@@ -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) {