• Alan Stern's avatar
    USB: OHCI: don't lose track of EDs when a controller dies · 977dcfdc
    Alan Stern authored
    
    
    This patch fixes a bug in ohci-hcd.  When an URB is unlinked, the
    corresponding Endpoint Descriptor is added to the ed_rm_list and taken
    off the hardware schedule.  Once the ED is no longer visible to the
    hardware, finish_unlinks() handles the URBs that were unlinked or have
    completed.  If any URBs remain attached to the ED, the ED is added
    back to the hardware schedule -- but only if the controller is
    running.
    
    This fails when a controller dies.  A non-empty ED does not get added
    back to the hardware schedule and does not remain on the ed_rm_list;
    ohci-hcd loses track of it.  The remaining URBs cannot be unlinked,
    which causes the USB stack to hang.
    
    The patch changes finish_unlinks() so that non-empty EDs remain on
    the ed_rm_list if the controller isn't running.  This requires moving
    some of the existing code around, to avoid modifying the ED's hardware
    fields more than once.
    Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
    CC: <stable@vger.kernel.org>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    977dcfdc
ohci-q.c 33.4 KB