lkml.org 
[lkml]   [2019]   [Jul]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 5.1 363/371] usb: Handle USB3 remote wakeup for LPM enabled devices correctly
    Date
    From: Lee, Chiasheng <chiasheng.lee@intel.com>

    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>

    ---
    drivers/usb/core/hub.c | 7 +++++--
    1 file changed, 5 insertions(+), 2 deletions(-)

    --- a/drivers/usb/core/hub.c
    +++ b/drivers/usb/core/hub.c
    @@ -3616,6 +3616,7 @@ static int hub_handle_remote_wakeup(stru
    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(stru
    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;
    }


    \
     
     \ /
      Last update: 2019-07-24 22:09    [W:5.467 / U:0.096 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site