From 9cf65991dd93ac3d5f97f536171c388918b7c1a9 Mon Sep 17 00:00:00 2001 From: Sarah Sharp Date: Tue, 3 Jul 2012 23:22:38 -0700 Subject: USB: Disable LPM while the device is unconfigured. 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 8306095fd2c1100e8244c09bf560f97aca5a311d "USB: Disable USB 3.0 LPM in critical sections." Signed-off-by: Sarah Sharp Cc: stable@vger.kernel.org --- drivers/usb/core/usb.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/usb/core/usb.c') diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c index 25d0c61c3f8..cd8fb44a3e1 100644 --- a/drivers/usb/core/usb.c +++ b/drivers/usb/core/usb.c @@ -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); -- cgit v1.2.3-70-g09d2