From 36caff5d795429c572443894e8789c2150dd796b Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Wed, 7 Nov 2012 10:31:30 -0500 Subject: [PATCH] USB: fix endpoint-disabling for failed config changes This patch (as1631) fixes a bug that shows up when a config change fails for a device under an xHCI controller. The controller needs to be told to disable the endpoints that have been enabled for the new config. The existing code does this, but before storing the information about which endpoints were enabled! As a result, any second attempt to install the new config is doomed to fail because xhci-hcd will refuse to enable an endpoint that is already enabled. The patch optimistically initializes the new endpoints' device structures before asking the device to switch to the new config. If the request fails then the endpoint information is already stored, so we can use usb_hcd_alloc_bandwidth() to disable the endpoints with no trouble. The rest of the error path is slightly more complex now; we have to disable the new interfaces and call put_device() rather than simply deallocating them. Signed-off-by: Alan Stern Reported-and-tested-by: Matthias Schniedermeyer CC: Sarah Sharp CC: Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/message.c | 54 ++++++++++++++++++++++---------------- 1 file changed, 31 insertions(+), 23 deletions(-) diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c index 1ed5afd91e6d..a557658f3223 100644 --- a/drivers/usb/core/message.c +++ b/drivers/usb/core/message.c @@ -1806,29 +1806,8 @@ int usb_set_configuration(struct usb_device *dev, int configuration) goto free_interfaces; } - ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), - USB_REQ_SET_CONFIGURATION, 0, configuration, 0, - NULL, 0, USB_CTRL_SET_TIMEOUT); - if (ret < 0) { - /* All the old state is gone, so what else can we do? - * The device is probably useless now anyway. - */ - cp = NULL; - } - - dev->actconfig = cp; - if (!cp) { - usb_set_device_state(dev, USB_STATE_ADDRESS); - usb_hcd_alloc_bandwidth(dev, NULL, NULL, NULL); - /* Leave LPM disabled while the device is unconfigured. */ - mutex_unlock(hcd->bandwidth_mutex); - usb_autosuspend_device(dev); - goto free_interfaces; - } - mutex_unlock(hcd->bandwidth_mutex); - usb_set_device_state(dev, USB_STATE_CONFIGURED); - - /* Initialize the new interface structures and the + /* + * Initialize the new interface structures and the * hc/hcd/usbcore interface/endpoint state. */ for (i = 0; i < nintf; ++i) { @@ -1872,6 +1851,35 @@ int usb_set_configuration(struct usb_device *dev, int configuration) } kfree(new_interfaces); + ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), + USB_REQ_SET_CONFIGURATION, 0, configuration, 0, + NULL, 0, USB_CTRL_SET_TIMEOUT); + if (ret < 0 && cp) { + /* + * All the old state is gone, so what else can we do? + * The device is probably useless now anyway. + */ + usb_hcd_alloc_bandwidth(dev, NULL, NULL, NULL); + for (i = 0; i < nintf; ++i) { + usb_disable_interface(dev, cp->interface[i], true); + put_device(&cp->interface[i]->dev); + cp->interface[i] = NULL; + } + cp = NULL; + } + + dev->actconfig = cp; + mutex_unlock(hcd->bandwidth_mutex); + + if (!cp) { + usb_set_device_state(dev, USB_STATE_ADDRESS); + + /* Leave LPM disabled while the device is unconfigured. */ + usb_autosuspend_device(dev); + return ret; + } + usb_set_device_state(dev, USB_STATE_CONFIGURED); + if (cp->string == NULL && !(dev->quirks & USB_QUIRK_CONFIG_INTF_STRINGS)) cp->string = usb_cache_string(dev, cp->desc.iConfiguration); -- 2.45.2