• Mathias Nyman's avatar
    xhci: workaround for hosts missing CAS bit · 346e9973
    Mathias Nyman authored
    If a device is unplugged and replugged during Sx system suspend
    some  Intel xHC hosts will overwrite the CAS (Cold attach status) flag
    and no device connection is noticed in resume.
    
    A device in this state can be identified in resume if its link state
    is in polling or compliance mode, and the current connect status is 0.
    A device in this state needs to be warm reset.
    
    Intel 100/c230 series PCH specification update Doc #332692-006 Errata #8
    
    Observed on Cherryview and Apollolake as they go into compliance mode
    if LFPS times out during polling, and re-plugged devices are not
    discovered at resume.
    Signed-off-by: default avatarMathias Nyman <mathias.nyman@linux.intel.com>
    CC: <stable@vger.kernel.org>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    346e9973
xhci-hub.c 43.4 KB