commit: 9cf65991dd93ac3d5f97f536171c388918b7c1a9 From: Sarah Sharp <[email protected]> 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 <[email protected]> Cc: [email protected] --- drivers/usb/core/message.c | 7 ++++--- drivers/usb/core/usb.c | 1 + 2 files changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c index 8b9d669..3723904 100644 --- a/drivers/usb/core/message.c +++ b/drivers/usb/core/message.c @@ -1792,14 +1792,15 @@ 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) { - usb_enable_lpm(dev); + if (dev->actconfig) + usb_enable_lpm(dev); mutex_unlock(hcd->bandwidth_mutex); usb_autosuspend_device(dev); goto free_interfaces; @@ -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; diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c index 25d0c61..cd8fb44 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); -- 1.7.3.4 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
