diff options
| author | Sudip Mukherjee <sudipm.mukherjee@gmail.com> | 2019-10-16 17:45:40 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-11-13 14:09:49 +0300 |
| commit | 60f8a59ddcdc7fb7c17180ba10d9c49bc91156c7 (patch) | |
| tree | 0e37345b5825da38fc0a3b39798cfe372e1bb79a | |
| parent | 231ec2f24dad18d021b361045bbd618ba62a274e (diff) | |
| download | linux-60f8a59ddcdc7fb7c17180ba10d9c49bc91156c7.tar.xz | |
parport: daisy: use new parport device model
Modify parport daisy driver to use the new parallel port device model.
Last attempt was '1aec4211204d ("parport: daisy: use new parport device
model")' which failed as daisy was also trying to load the low level
driver and that resulted in a deadlock.
Cc: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Tested-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20191016144540.18810-4-sudipm.mukherjee@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/parport/daisy.c | 40 |
1 files changed, 39 insertions, 1 deletions
diff --git a/drivers/parport/daisy.c b/drivers/parport/daisy.c index 5484a46dafda..3b00e2c8e2e9 100644 --- a/drivers/parport/daisy.c +++ b/drivers/parport/daisy.c @@ -45,6 +45,7 @@ static struct daisydev { static DEFINE_SPINLOCK(topology_lock); static int numdevs; +static bool daisy_init_done; /* Forward-declaration of lower-level functions. */ static int mux_present(struct parport *port); @@ -87,6 +88,24 @@ static struct parport *clone_parport(struct parport *real, int muxport) return extra; } +static int daisy_drv_probe(struct pardevice *par_dev) +{ + struct device_driver *drv = par_dev->dev.driver; + + if (strcmp(drv->name, "daisy_drv")) + return -ENODEV; + if (strcmp(par_dev->name, daisy_dev_name)) + return -ENODEV; + + return 0; +} + +static struct parport_driver daisy_driver = { + .name = "daisy_drv", + .probe = daisy_drv_probe, + .devmodel = true, +}; + /* Discover the IEEE1284.3 topology on a port -- muxes and daisy chains. * Return value is number of devices actually detected. */ int parport_daisy_init(struct parport *port) @@ -98,6 +117,23 @@ int parport_daisy_init(struct parport *port) int i; int last_try = 0; + if (!daisy_init_done) { + /* + * flag should be marked true first as + * parport_register_driver() might try to load the low + * level driver which will lead to announcing new ports + * and which will again come back here at + * parport_daisy_init() + */ + daisy_init_done = true; + i = parport_register_driver(&daisy_driver); + if (i) { + pr_err("daisy registration failed\n"); + daisy_init_done = false; + return i; + } + } + again: /* Because this is called before any other devices exist, * we don't have to claim exclusive access. */ @@ -213,10 +249,12 @@ void parport_daisy_fini(struct parport *port) struct pardevice *parport_open(int devnum, const char *name) { struct daisydev *p = topology; + struct pardev_cb par_cb; struct parport *port; struct pardevice *dev; int daisy; + memset(&par_cb, 0, sizeof(par_cb)); spin_lock(&topology_lock); while (p && p->devnum != devnum) p = p->next; @@ -230,7 +268,7 @@ struct pardevice *parport_open(int devnum, const char *name) port = parport_get_port(p->port); spin_unlock(&topology_lock); - dev = parport_register_device(port, name, NULL, NULL, NULL, 0, NULL); + dev = parport_register_dev_model(port, name, &par_cb, devnum); parport_put_port(port); if (!dev) return NULL; |