From: "Lee, Chiasheng" chiasheng.lee@intel.com
With Link Power Management (LPM) enabled USB3 links transition to low power U1/U2 link states from U0 state automatically.
Current hub code detects USB3 remote wakeups by checking if the software state still shows suspended, but the link has transitioned from suspended U3 to enabled U0 state.
As it takes some time before the hub thread reads the port link state after a USB3 wake notification, the link may have transitioned from U0 to U1/U2, and wake is not detected by hub code.
Fix this by handling U1/U2 states in the same way as U0 in USB3 wakeup handling
This patch should be added to stable kernels since 4.13 where LPM was kept enabled during suspend/resume
Cc: stable@vger.kernel.org # v4.13+ Signed-off-by: Lee, Chiasheng chiasheng.lee@intel.com Signed-off-by: Mathias Nyman mathias.nyman@linux.intel.com --- drivers/usb/core/hub.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 2f94568..2c8e60c 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -3617,6 +3617,7 @@ static int hub_handle_remote_wakeup(struct usb_hub *hub, unsigned int port, struct usb_device *hdev; struct usb_device *udev; int connect_change = 0; + u16 link_state; int ret;
hdev = hub->hdev; @@ -3626,9 +3627,11 @@ static int hub_handle_remote_wakeup(struct usb_hub *hub, unsigned int port, return 0; usb_clear_port_feature(hdev, port, USB_PORT_FEAT_C_SUSPEND); } else { + link_state = portstatus & USB_PORT_STAT_LINK_STATE; if (!udev || udev->state != USB_STATE_SUSPENDED || - (portstatus & USB_PORT_STAT_LINK_STATE) != - USB_SS_PORT_LS_U0) + (link_state != USB_SS_PORT_LS_U0 && + link_state != USB_SS_PORT_LS_U1 && + link_state != USB_SS_PORT_LS_U2)) return 0; }