• Hans Verkuil's avatar
    [media] gspca: Fix locking issues related to suspend/resume · 254902b0
    Hans Verkuil authored
    There are two bugs here: first the calls to stop0 (in gspca_suspend) and
    gspca_init_transfer (in gspca_resume) need to be called with the usb_lock held.
    That's true for the other places they are called and it is what subdrivers
    expect. Quite a few will unlock the usb_lock in stop0 while waiting for a
    worker thread to finish, and if usb_lock isn't held then that can cause a
    kernel oops.
    
    The other problem is that a worker thread needs to detect that it has to
    halt due to a suspend. Otherwise it will just go on looping. So add tests
    against gspca_dev->frozen in the worker threads that need it.
    
    Hdg, 2 minor changes:
    1) The finepix device is ok with stopping reading a frame halfway through,
       so add frozen checks in all places where we also check if we're still
       streaming
    2) Use gspca_dev->dev instead of gspca_dev->present to check for disconnect
       in all touched drivers. I plan to do this everywhere in the future, and
       most relevant lines in the touched drivers are already modified by this
       patch.
    Signed-off-by: default avatarHans Verkuil <hans.verkuil@cisco.com>
    Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
    Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
    254902b0
sq905.c 12.7 KB