USB: Disable LPM while the device is unconfigured. (9cf65991) · Commits · 戴 / test

The USB 3.0 Set/Clear Feature U1/U2 Enable cannot be sent to a device in the Default or Addressed state. It can only be sent to a configured device. Change the USB core to initialize the LPM disable count to 1 (disabled), which reflects this limitation. Change usb_set_configuration() to ensure that if the device is unconfigured on entry, usb_lpm_disable() is not called. This avoids sending the Clear Feature U1/U2 when the device is in the Addressed state. When usb_set_configuration() exits with a successfully installed configuration, usb_lpm_enable() will be called. Once the new configuration is installed, make sure usb_set_configuration() only calls usb_enable_lpm() if the device moved to the Configured state. If we have unconfigured the device by sending it a Set Configuration for config 0, don't enable LPM. This commit should be backported to kernels as old as 3.5, that contain the commit "USB: Disable USB 3.0 LPM in critical sections." Signed-off-by:

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

drivers/usb/core/message.c

+4 −3

Original line number	Diff line number	Diff line
		@@ -1792,13 +1792,14 @@ free_interfaces:
		* installed, so that the xHCI driver can recalculate the U1/U2
		* timeouts.
		*/
		if (usb_disable_lpm(dev)) {
		if (dev->actconfig && usb_disable_lpm(dev)) {
		dev_err(&dev->dev, "%s Failed to disable LPM\n.", __func__);
		mutex_unlock(hcd->bandwidth_mutex);
		return -ENOMEM;
		}
		ret = usb_hcd_alloc_bandwidth(dev, cp, NULL, NULL);
		if (ret < 0) {
		if (dev->actconfig)
		usb_enable_lpm(dev);
		mutex_unlock(hcd->bandwidth_mutex);
		usb_autosuspend_device(dev);
		@@ -1819,7 +1820,7 @@ free_interfaces:
		if (!cp) {
		usb_set_device_state(dev, USB_STATE_ADDRESS);
		usb_hcd_alloc_bandwidth(dev, NULL, NULL, NULL);
		usb_enable_lpm(dev);
		/* Leave LPM disabled while the device is unconfigured. */
		mutex_unlock(hcd->bandwidth_mutex);
		usb_autosuspend_device(dev);
		goto free_interfaces;

drivers/usb/core/usb.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -396,6 +396,7 @@ struct usb_device usb_alloc_dev(struct usb_device parent,
		dev->dev.dma_mask = bus->controller->dma_mask;
		set_dev_node(&dev->dev, dev_to_node(bus->controller));
		dev->state = USB_STATE_ATTACHED;
		dev->lpm_disable_count = 1;
		atomic_set(&dev->urbnum, 0);

		INIT_LIST_HEAD(&dev->ep0.urb_list);

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