| From | Greg Kroah-Hartman <> | Subject | [ 032/122] USB: Disable LPM while the device is unconfigured. | Date | Tue, 7 Aug 2012 15:25:20 -0700 |
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From: Greg KH <gregkh@linuxfoundation.org>
3.5-stable review patch. If anyone has any objections, please let me know.
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From: Sarah Sharp <sarah.a.sharp@linux.intel.com>
commit 9cf65991dd93ac3d5f97f536171c388918b7c1a9 upstream.
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 <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/usb/core/message.c | 7 ++++--- drivers/usb/core/usb.c | 1 + 2 files changed, 5 insertions(+), 3 deletions(-)
--- a/drivers/usb/core/message.c +++ b/drivers/usb/core/message.c @@ -1791,14 +1791,15 @@ 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; @@ -1818,7 +1819,7 @@ 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; --- a/drivers/usb/core/usb.c +++ b/drivers/usb/core/usb.c @@ -396,6 +396,7 @@ struct usb_device *usb_alloc_dev(struct 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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