EHCI: always clear the STS_FLR status bit

This patch (as1544) fixes a problem affecting some EHCI controllers.
They can generate interrupts whenever the STS_FLR status bit is turned
on, even though that bit is masked out in the Interrupt Enable
register.

Since the driver doesn't use STS_FLR anyway, the patch changes the
interrupt routine to clear that bit whenever it is set, rather than
leaving it alone.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-and-tested-by: Tomoya MORINAGA <tomoya.rohm@gmail.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Alan Stern 2012-04-18 11:33:00 -04:00 committed by Greg Kroah-Hartman
parent dc75ce9d92
commit 2fbe2bf1fd
1 changed files with 6 additions and 1 deletions

View File

@ -858,8 +858,13 @@ static irqreturn_t ehci_irq (struct usb_hcd *hcd)
goto dead;
}
/*
* We don't use STS_FLR, but some controllers don't like it to
* remain on, so mask it out along with the other status bits.
*/
masked_status = status & (INTR_MASK | STS_FLR);
/* Shared IRQ? */
masked_status = status & INTR_MASK;
if (!masked_status || unlikely(ehci->rh_state == EHCI_RH_HALTED)) {
spin_unlock(&ehci->lock);
return IRQ_NONE;