Merge branch 'nfsd-next' of git://linux-nfs.org/~bfields/linux

[~andy/linux] / drivers / usb / host / ehci-hcd.c

diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index 471142725ffe1cd42f92b2ad0883fa925c715a2a..81cda09b47e3127772e51cbc5c57eab7761c4a52 100644 (file)
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -685,8 +685,15 @@ static irqreturn_t ehci_irq (struct usb_hcd *hcd)
        struct ehci_hcd         *ehci = hcd_to_ehci (hcd);
        u32                     status, masked_status, pcd_status = 0, cmd;
        int                     bh;
+       unsigned long           flags;
 
-       spin_lock (&ehci->lock);
+       /*
+        * For threadirqs option we use spin_lock_irqsave() variant to prevent
+        * deadlock with ehci hrtimer callback, because hrtimer callbacks run
+        * in interrupt context even when threadirqs is specified. We can go
+        * back to spin_lock() variant when hrtimer callbacks become threaded.
+        */
+       spin_lock_irqsave(&ehci->lock, flags);
 
        status = ehci_readl(ehci, &ehci->regs->status);
 
@@ -704,7 +711,7 @@ static irqreturn_t ehci_irq (struct usb_hcd *hcd)
 
        /* Shared IRQ? */
        if (!masked_status || unlikely(ehci->rh_state == EHCI_RH_HALTED)) {
-               spin_unlock(&ehci->lock);
+               spin_unlock_irqrestore(&ehci->lock, flags);
                return IRQ_NONE;
        }
 
@@ -815,7 +822,7 @@ dead:
 
        if (bh)
                ehci_work (ehci);
-       spin_unlock (&ehci->lock);
+       spin_unlock_irqrestore(&ehci->lock, flags);
        if (pcd_status)
                usb_hcd_poll_rh_status(hcd);
        return IRQ_HANDLED;