[patch 01/28] USB: fix hcd interrupt disabling

[Greg KH]

2.6.25-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Geoff Levand <geoffrey.levand@xxxxxxxxxxx>

commit 83a798207361cc26385187b2e71efa2b5d75de7f upstream

Commit de85422b94ddb23c021126815ea49414047c13dc, 'USB: fix interrupt
disabling for HCDs with shared interrupt handlers' changed usb_add_hcd()
to strip IRQF_DISABLED from irqflags prior to calling request_irq()
with the justification that such a removal was necessary for shared
interrupts to work properly.  Unfortunately, the change in that commit
unconditionally removes the IRQF_DISABLED flag, causing problems on
platforms that don't use a shared interrupt but require IRQF_DISABLED.
This change adds a check for IRQF_SHARED prior to removing the
IRQF_DISABLED flag.

Fixes the PS3 system startup hang reported with recent Fedora and
OpenSUSE kernels.

Note that this problem is hidden when CONFIG_LOCKDEP=y (ps3_defconfig),
as local_irq_enable_in_hardirq() is defined as a null statement for
that config.

Signed-off-by: Geoff Levand <geoffrey.levand@xxxxxxxxxxx>
Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Cc: Stefan Becker <Stefan.Becker@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 drivers/usb/core/hcd.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -1877,7 +1877,8 @@ int usb_add_hcd(struct usb_hcd *hcd,
 		 * with IRQF_SHARED. As usb_hcd_irq() will always disable
 		 * interrupts we can remove it here.
 		 */
-		irqflags &= ~IRQF_DISABLED;
+		if (irqflags & IRQF_SHARED)
+			irqflags &= ~IRQF_DISABLED;
 
 		snprintf(hcd->irq_descr, sizeof(hcd->irq_descr), "%s:usb%d",
 				hcd->driver->description, hcd->self.busnum);

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