USB2 LPM is disabled when device begin to suspend and enabled after device is resumed. That's because USB spec does not define the transition from U1/U2 state to U3 state. If usb_port_suspend() fails, usb_port_resume() is never called, and USB2 LPM is disabled in this situation. Enable USB2 LPM if port suspend fails. Signed-off-by: Andiry Xu <andiry.xu@xxxxxxxxx> --- drivers/usb/core/hub.c | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-) diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index ec6c97d..c8e0704 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -2499,6 +2499,10 @@ int usb_port_suspend(struct usb_device *udev, pm_message_t msg) NULL, 0, USB_CTRL_SET_TIMEOUT); + /* Try to enable USB2 hardware LPM again */ + if (udev->usb2_hw_lpm_capable == 1) + usb_set_usb2_hardware_lpm(udev, 1); + /* System sleep transitions should never fail */ if (!PMSG_IS_AUTO(msg)) status = 0; -- 1.7.4.1 -- 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
