xhci: Don't submit commands or URBs to halted hosts. (7bd89b40) · Commits · 戴 / test

Commit "USB: Free bandwidth when usb_disable_device is called" caused a bit of an issue when the xHCI host controller driver is unloaded. It changed the USB core to remove all endpoints when a USB device is disabled. When the driver is unloaded, it will remove the SuperSpeed split root hub, which will disable all devices under that roothub and then halt the host controller. When the second High Speed split roothub is removed, the USB core will attempt to disable the endpoints, which will submit a Configure Endpoint command to a halted host controller. The command will eventually time out, but it makes the xHCI driver unload take *minutes* if there are a couple of USB 1.1/2.0 devices attached. We must halt the host controller when the SuperSpeed roothub is removed, because we can't allow any interrupts from things like port status changes. Make several different functions not submit commands or URBs to the host controller when the host is halted, by adding a check in xhci_check_args(). xhci_check_args() is used by these functions: xhci.c-int xhci_urb_enqueue() xhci.c-int xhci_drop_endpoint() xhci.c-int xhci_add_endpoint() xhci.c-int xhci_check_bandwidth() xhci.c-void xhci_reset_bandwidth() xhci.c-static int xhci_check_streams_endpoint() xhci.c-int xhci_discover_or_reset_device() It's also used by xhci_free_dev(). However, we have to take special care in that case, because we want the device memory to be freed if the host controller is halted. This patch should be backported to the 2.6.39 and 3.0 kernel. Signed-off-by:

Sarah Sharp <sarah.a.sharp@linux.intel.com> Cc: stable@kernel.org

drivers/usb/host/xhci.c

+14 −5

Original line number	Diff line number	Diff line
		@@ -345,7 +345,8 @@ static void xhci_event_ring_work(unsigned long arg)
		spin_lock_irqsave(&xhci->lock, flags);
		temp = xhci_readl(xhci, &xhci->op_regs->status);
		xhci_dbg(xhci, "op reg status = 0x%x\n", temp);
		if (temp == 0xffffffff \|\| (xhci->xhc_state & XHCI_STATE_DYING)) {
		if (temp == 0xffffffff \|\| (xhci->xhc_state & XHCI_STATE_DYING) \|\|
		(xhci->xhc_state & XHCI_STATE_HALTED)) {
		xhci_dbg(xhci, "HW died, polling stopped.\n");
		spin_unlock_irqrestore(&xhci->lock, flags);
		return;
		@@ -939,8 +940,11 @@ static int xhci_check_args(struct usb_hcd hcd, struct usb_device udev,
		return 0;
		}

		if (check_virt_dev) {
		xhci = hcd_to_xhci(hcd);
		if (xhci->xhc_state & XHCI_STATE_HALTED)
		return -ENODEV;

		if (check_virt_dev) {
		if (!udev->slot_id \|\| !xhci->devs
		\|\| !xhci->devs[udev->slot_id]) {
		printk(KERN_DEBUG "xHCI %s called with unaddressed "
		@@ -1242,7 +1246,8 @@ int xhci_urb_dequeue(struct usb_hcd hcd, struct urb urb, int status)
		xhci_urb_free_priv(xhci, urb_priv);
		return ret;
		}
		if (xhci->xhc_state & XHCI_STATE_DYING) {
		if ((xhci->xhc_state & XHCI_STATE_DYING) \|\|
		(xhci->xhc_state & XHCI_STATE_HALTED)) {
		xhci_dbg(xhci, "Ep 0x%x: URB %p to be canceled on "
		"non-responsive xHCI host.\n",
		urb->ep->desc.bEndpointAddress, urb);
		@@ -2665,7 +2670,10 @@ void xhci_free_dev(struct usb_hcd hcd, struct usb_device udev)
		int i, ret;

		ret = xhci_check_args(hcd, udev, NULL, 0, true, __func__);
		if (ret <= 0)
		/* If the host is halted due to driver unload, we still need to free the
		* device.
		*/
		if (ret <= 0 && ret != -ENODEV)
		return;

		virt_dev = xhci->devs[udev->slot_id];
		@@ -2679,7 +2687,8 @@ void xhci_free_dev(struct usb_hcd hcd, struct usb_device udev)
		spin_lock_irqsave(&xhci->lock, flags);
		/* Don't disable the slot if the host controller is dead. */
		state = xhci_readl(xhci, &xhci->op_regs->status);
		if (state == 0xffffffff \|\| (xhci->xhc_state & XHCI_STATE_DYING)) {
		if (state == 0xffffffff \|\| (xhci->xhc_state & XHCI_STATE_DYING) \|\|
		(xhci->xhc_state & XHCI_STATE_HALTED)) {
		xhci_free_virt_device(xhci, udev->slot_id);
		spin_unlock_irqrestore(&xhci->lock, flags);
		return;

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