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authorLee, Chiasheng <chiasheng.lee@intel.com>2019-06-20 10:56:04 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-07-26 10:13:07 +0300
commit24d22d774481e7d586534937b0f24d0a0dfb7e40 (patch)
tree704899b7896c07e0744e13a760e8356501e36041
parent584cd9936ac1c52517711dbc0d6f380177069c97 (diff)
downloadlinux-24d22d774481e7d586534937b0f24d0a0dfb7e40.tar.xz
usb: Handle USB3 remote wakeup for LPM enabled devices correctly
commit e244c4699f859cf7149b0781b1894c7996a8a1df upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/usb/core/hub.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 310eef451db8..b10d14af6416 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -3616,6 +3616,7 @@ 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;
@@ -3625,9 +3626,11 @@ 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;
}