The marvell cam driver retained just enough of the owner-tracking logic
from cafe_ccic to be broken; it could, conceivably, cause the driver to
release DMA memory while the controller is still active.  Simply remove the
remaining pieces and ensure that the controller is stopped before we free
things.
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
                        singles, delivered);
        mutex_lock(&cam->s_mutex);
        (cam->users)--;
-       if (filp == cam->owner) {
-               mcam_ctlr_stop_dma(cam);
-               cam->owner = NULL;
-       }
        if (cam->users == 0) {
+               mcam_ctlr_stop_dma(cam);
                mcam_cleanup_vb2(cam);
                mcam_ctlr_power_down(cam);
                if (cam->buffer_mode == B_vmalloc && alloc_bufs_at_read)
 
        enum mcam_state state;
        unsigned long flags;            /* Buffer status, mainly (dev_lock) */
        int users;                      /* How many open FDs */
-       struct file *owner;             /* Who has data access (v4l2) */
 
        /*
         * Subsystem structures.