From ba297edde4dd7376832bafb23e032a40d5928b56 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Wed, 9 Jun 2010 17:34:39 -0400 Subject: [PATCH] USB: UHCI: acquire spinlock before calling start_rh() This patch (as1392) fixes a bug in uhci-hcd: The start_rh() routine is supposed to be called with the private spinlock held. If an IRQ comes in at just the wrong time, the driver will think the controller has died when in fact it simply hasn't start yet. The patch also addresses some issues that may prevent an URB from being unlinked after the controller has stopped. This is an abnormal occurrence (ordinarily the controller stops only when the entire bus is suspended and hence there are no active URBs), so the pathways haven't gotten much testing. These two changes may be a little more than is strictly necessary, but clearly they won't hurt. Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/uhci-hcd.c | 2 ++ drivers/usb/host/uhci-q.c | 4 ++-- 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/usb/host/uhci-hcd.c b/drivers/usb/host/uhci-hcd.c index 6637e52736dd..d1dce2166eff 100644 --- a/drivers/usb/host/uhci-hcd.c +++ b/drivers/usb/host/uhci-hcd.c @@ -691,7 +691,9 @@ static int uhci_start(struct usb_hcd *hcd) configure_hc(uhci); uhci->is_initialized = 1; + spin_lock_irq(&uhci->lock); start_rh(uhci); + spin_unlock_irq(&uhci->lock); return 0; /* diff --git a/drivers/usb/host/uhci-q.c b/drivers/usb/host/uhci-q.c index acd582c02802..d3ade4018487 100644 --- a/drivers/usb/host/uhci-q.c +++ b/drivers/usb/host/uhci-q.c @@ -565,7 +565,7 @@ static void uhci_unlink_qh(struct uhci_hcd *uhci, struct uhci_qh *qh) qh->unlink_frame = uhci->frame_number; /* Force an interrupt so we know when the QH is fully unlinked */ - if (list_empty(&uhci->skel_unlink_qh->node)) + if (list_empty(&uhci->skel_unlink_qh->node) || uhci->is_stopped) uhci_set_next_interrupt(uhci); /* Move the QH from its old list to the end of the unlinking list */ @@ -1667,7 +1667,7 @@ static int uhci_advance_check(struct uhci_hcd *uhci, struct uhci_qh *qh) qh->advance_jiffies = jiffies; goto done; } - ret = 0; + ret = uhci->is_stopped; } /* The queue hasn't advanced; check for timeout */