as of now, we are not checking if attach or parport_register_driver has succeeded or failed. But attach can fail in the places where they have been used. Lets check the return of attach, and if attach fails then parport_register_driver should also fail. We can have multiple parallel port so we only mark attach as failed only if it has never returned a 0.
Signed-off-by: Sudip Mukherjee sudip@vectorindia.org --- drivers/parport/share.c | 20 +++++++++++++++----- include/linux/parport.h | 2 +- 2 files changed, 16 insertions(+), 6 deletions(-)
diff --git a/drivers/parport/share.c b/drivers/parport/share.c index 3fa6624..640ce41 100644 --- a/drivers/parport/share.c +++ b/drivers/parport/share.c @@ -148,23 +148,33 @@ static void get_lowlevel_driver (void) * callback, but if the driver wants to take a copy of the * pointer it must call parport_get_port() to do so. * - * Returns 0 on success. Currently it always succeeds. + * Returns 0 on success. **/
int parport_register_driver (struct parport_driver *drv) { struct parport *port; + int ret, err; + bool attached = false;
if (list_empty(&portlist)) get_lowlevel_driver ();
mutex_lock(®istration_lock); - list_for_each_entry(port, &portlist, list) - drv->attach(port); - list_add(&drv->list, &drivers); + list_for_each_entry(port, &portlist, list) { + err = drv->attach(port); + if (err == 0) + attached = true; + else + ret = err; + } + if (attached) { + list_add(&drv->list, &drivers); + ret = 0; + } mutex_unlock(®istration_lock);
- return 0; + return ret; }
/** diff --git a/include/linux/parport.h b/include/linux/parport.h index c22f125..9411065 100644 --- a/include/linux/parport.h +++ b/include/linux/parport.h @@ -249,7 +249,7 @@ struct parport {
struct parport_driver { const char *name; - void (*attach) (struct parport *); + int (*attach)(struct parport *); void (*detach) (struct parport *); struct list_head list; };