[PATCH][TRUSTY] Revert "usb: ehci: fix deadlock when threadirqs option is used"

[Colin King]

From: Colin Ian King <colin.king at canonical.com>

This patch unfortunately breaks USB on my Lenovo x230 and on a Lenovo
T440. I guess it may break it on a wider range of machines too. I'm
requesting that it is reverted.

This reverts commit 65482e0c807a50dc3ec9d59a7465801f9c56bf52.
---
 drivers/usb/host/ehci-hcd.c | 13 +++----------
 1 file changed, 3 insertions(+), 10 deletions(-)

diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index 4dfd6fb..e8ba4c4 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -686,15 +686,8 @@ 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;
 
-	/*
-	 * 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);
+	spin_lock (&ehci->lock);
 
 	status = ehci_readl(ehci, &ehci->regs->status);
 
@@ -712,7 +705,7 @@ static irqreturn_t ehci_irq (struct usb_hcd *hcd)
 
 	/* Shared IRQ? */
 	if (!masked_status || unlikely(ehci->rh_state == EHCI_RH_HALTED)) {
-		spin_unlock_irqrestore(&ehci->lock, flags);
+		spin_unlock(&ehci->lock);
 		return IRQ_NONE;
 	}
 
@@ -830,7 +823,7 @@ dead:
 
 	if (bh)
 		ehci_work (ehci);
-	spin_unlock_irqrestore(&ehci->lock, flags);
+	spin_unlock (&ehci->lock);
 	if (pcd_status)
 		usb_hcd_poll_rh_status(hcd);
 	return IRQ_HANDLED;
-- 
1.9.0