MUSB: Add back irq_work for cable events

This is needed to avoid sleeping function called from invalid context.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>

drivers/usb/musb/musb_gadget.c

@@ -973,7 +973,7 @@ static int musb_gadget_enable(struct usb_ep *ep,
 			pEnd->dma ? "dma, " : "",
 			pEnd->wPacketSize);
 
-	sysfs_notify(&pThis->controller->kobj, NULL, "cable");
+	schedule_work(&pThis->irq_work);
 
 fail:
 	spin_unlock_irqrestore(&pThis->Lock, flags);
@@ -1016,7 +1016,7 @@ static int musb_gadget_disable(struct usb_ep *ep)
 	/* abort all pending DMA and requests */
 	nuke(pEnd, -ESHUTDOWN);
 
-	sysfs_notify(&pThis->controller->kobj, NULL, "cable");
+	schedule_work(&pThis->irq_work);
 
 	spin_unlock_irqrestore(&(pThis->Lock), flags);
 

drivers/usb/musb/musbdefs.h

@@ -392,6 +392,7 @@ struct musb {
 	spinlock_t		Lock;
 	struct clk		*clock;
 	irqreturn_t		(*isr)(int, void *, struct pt_regs *);
+	struct work_struct	irq_work;
 
 #ifdef CONFIG_USB_MUSB_HDRC_HCD
 

drivers/usb/musb/plat_uds.c

@@ -530,7 +530,7 @@ static irqreturn_t musb_stage0_irq(struct musb * pThis, u8 bIntrUSB,
 						(power & MGC_M_POWER_SUSPENDM)
 						? TRUE : FALSE);
 
-			sysfs_notify(&pThis->controller->kobj, NULL, "cable");
+			schedule_work(&pThis->irq_work);
 		}
 
 		handled = IRQ_HANDLED;
@@ -615,7 +615,7 @@ static irqreturn_t musb_stage2_irq(struct musb * pThis, u8 bIntrUSB,
 		/* REVISIT all OTG state machine transitions */
 		otg_input_changed_X(pThis, FALSE, FALSE);
 
-		sysfs_notify(&pThis->controller->kobj, NULL, "cable");
+		schedule_work(&pThis->irq_work);
 	}
 
 	if (bIntrUSB & MGC_M_INTR_SUSPEND) {
@@ -1461,6 +1461,14 @@ static DEVICE_ATTR(cable, S_IRUGO, musb_cable_show, NULL);
 
 #endif
 
+/* Only used to provide cable state change events */
+static void musb_irq_work(void *data)
+{
+	struct musb *musb = (struct musb *)data;
+
+	sysfs_notify(&musb->controller->kobj, NULL, "cable");
+}
+
 /* --------------------------------------------------------------------------
  * Init support
  */
@@ -1736,6 +1744,8 @@ fail:
 		return status;
 	}
 
+	INIT_WORK(&pThis->irq_work, musb_irq_work, pThis);
+
 #ifdef CONFIG_SYSFS
 	device_create_file(dev, &dev_attr_mode);
 	device_create_file(dev, &dev_attr_cable);

drivers/usb/musb/tusb6010.c

@@ -344,7 +344,7 @@ tusb_otg_ints(struct musb *musb, u32 int_src, void __iomem *base)
 			DBG(1, "%s\n", musb->is_active
 					? "b_peripheral" : "b_idle");
 
-			sysfs_notify(&musb->controller->kobj, NULL, "cable");
+			schedule_work(&musb->irq_work);
 		}
 	}
 
@@ -398,7 +398,7 @@ static irqreturn_t tusb_interrupt(int irq, void *__hci, struct pt_regs *r)
 		musb_writel(base, TUSB_PRCM_WAKEUP_CLEAR, reg);
 		if (reg & ~TUSB_PRCM_WNORCS) {
 			musb->is_active = 1;
-			sysfs_notify(&musb->controller->kobj, NULL, "cable");
+			schedule_work(&musb->irq_work);
 		}
 		DBG(3, "wake %sactive %02x\n",
 				musb->is_active ? "" : "in", reg);