From: Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx> When there's an xHCI host power loss after a suspend from memory, the USB core attempts to reset and verify the USB devices that are attached to the system. The xHCI driver has to reallocate those devices, since the hardware lost all knowledge of them during the power loss. When a hub is plugged in, and the host loses power, the xHCI hardware structures are not updated to say the device is a hub. This is usually done in hub_configure() when the USB hub is detected. That function is skipped during a reset and verify by the USB core, since the core restores the old configuration and alternate settings, and the hub driver has no idea this happened. This bug makes the xHCI host controller reject the enumeration of low speed devices under the resumed hub. Therefore, make the USB core re-setup the internal xHCI hub device information by calling update_hub_device() when hub_activate() is called for a hub reset resume. After a host power loss, all devices under the roothub get a reset-resume or a disconnect. This patch should be queued for the 2.6.37 stable tree. Signed-off-by: Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx> Cc: stable@xxxxxxxxxx --- drivers/usb/core/hub.c | 21 +++++++++++++++++++++ 1 files changed, 21 insertions(+), 0 deletions(-) diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index b98efae..4310cc4 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -676,6 +676,8 @@ static void hub_init_func3(struct work_struct *ws); static void hub_activate(struct usb_hub *hub, enum hub_activation_type type) { struct usb_device *hdev = hub->hdev; + struct usb_hcd *hcd; + int ret; int port1; int status; bool need_debounce_delay = false; @@ -714,6 +716,25 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type) usb_autopm_get_interface_no_resume( to_usb_interface(hub->intfdev)); return; /* Continues at init2: below */ + } else if (type == HUB_RESET_RESUME) { + /* The internal host controller state for the hub device + * may be gone after a host power loss on system resume. + * Update the device's info so the HW knows it's a hub. + */ + hcd = bus_to_hcd(hdev->bus); + if (hcd->driver->update_hub_device) { + ret = hcd->driver->update_hub_device(hcd, hdev, + &hub->tt, GFP_NOIO); + if (ret < 0) { + dev_err(hub->intfdev, "Host not " + "accepting hub info " + "update.\n"); + dev_err(hub->intfdev, "LS/FS devices " + "and hubs may not work " + "under this hub\n."); + } + } + hub_power_on(hub, true); } else { hub_power_on(hub, true); } -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html