On Tue, Sep 06, 2022 at 11:35:45AM +0800, 'Guanjun' wrote: . > +static const struct file_operations ycc_fops = { > + .open = ycc_cdev_open, > + .release = ycc_cdev_release, > + .unlocked_ioctl = ycc_cdev_ioctl, > +}; What is this device for? It doesn't seem to do anything so why not jsut drop it? Thanks, -- Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt