From: Alan Stern Date: Wed, 9 Jun 2010 21:34:39 +0000 (-0400) Subject: USB: UHCI: acquire spinlock before calling start_rh() X-Git-Tag: upstream/snapshot3+hdmi~13509^2~144 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=ba297edde4dd7376832bafb23e032a40d5928b56;p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.git 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 --- diff --git a/drivers/usb/host/uhci-hcd.c b/drivers/usb/host/uhci-hcd.c index 6637e52..d1dce21 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 acd582c..d3ade40 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 */