Merge tag 'usb-3.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb

torvalds · torvalds · commit a53c8ceb01c5 · 2014-03-02T15:15:07.000-08:00
Pull USB fixes from Greg KH:
 "Here are 2 USB patches for 3.14-rc5, one a new device id, and the
  other fixes a reported problem with threaded irqs and the USB EHCI
  driver"

* tag 'usb-3.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  usb: ehci: fix deadlock when threadirqs option is used
  USB: ftdi_sio: add Cressi Leonardo PID
diff --git 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 @@ static irqreturn_t ehci_irq (struct usb_hcd *hcd)
 
 	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;
diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
@@ -907,6 +907,8 @@ static const struct usb_device_id id_table_combined[] = {
 	/* Crucible Devices */
 	{ USB_DEVICE(FTDI_VID, FTDI_CT_COMET_PID) },
 	{ USB_DEVICE(FTDI_VID, FTDI_Z3X_PID) },
+	/* Cressi Devices */
+	{ USB_DEVICE(FTDI_VID, FTDI_CRESSI_PID) },
 	{ }					/* Terminating entry */
 };
 
diff --git a/drivers/usb/serial/ftdi_sio_ids.h b/drivers/usb/serial/ftdi_sio_ids.h
@@ -1320,3 +1320,9 @@
  * Manufacturer: Smart GSM Team
  */
 #define FTDI_Z3X_PID		0x0011
+
+/*
+ * Product: Cressi PC Interface
+ * Manufacturer: Cressi
+ */
+#define FTDI_CRESSI_PID		0x87d0
