From 2fbe2bf1fd37f9d99950bd8d8093623cf22cf08b Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Wed, 18 Apr 2012 11:33:00 -0400 Subject: [PATCH] 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 Reported-and-tested-by: Tomoya MORINAGA Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/ehci-hcd.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c index 95ca07a8e1b5..4a3bc5b7a06f 100644 --- a/drivers/usb/host/ehci-hcd.c +++ b/drivers/usb/host/ehci-hcd.c @@ -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; -- 2.20.1