On Sun, 21 Aug 2016 16:50:20 +0200 Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > On Fri, Aug 19, 2016 at 01:09:35PM +0200, Christian Gromm wrote: > > This patch moves the initialization of the idr structure towards the end > > of the module's init routine. This keeps the code compact and eliminates > > the need of having to call ida_destroy() in case the function exits with > > an exception. > > > > Signed-off-by: Christian Gromm <christian.gromm@xxxxxxxxxxxxx> > > --- > > drivers/staging/most/aim-cdev/cdev.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/staging/most/aim-cdev/cdev.c b/drivers/staging/most/aim-cdev/cdev.c > > index db6f458..3864009 100644 > > --- a/drivers/staging/most/aim-cdev/cdev.c > > +++ b/drivers/staging/most/aim-cdev/cdev.c > > @@ -505,7 +505,6 @@ static int __init mod_init(void) > > > > INIT_LIST_HEAD(&channel_list); > > spin_lock_init(&ch_list_lock); > > - ida_init(&minor_id); > > > > err = alloc_chrdev_region(&aim_devno, 0, 50, "cdev"); > > if (err < 0) > > @@ -521,6 +520,7 @@ static int __init mod_init(void) > > err = most_register_aim(&cdev_aim); > > if (err) > > goto dest_class; > > + ida_init(&minor_id); > > But can't the minor_id be used before this call? most_register_aim() > could call into a driver and have a cdev be wanted, right? No. After calling most_register_aim() the device appears in sysfs. Then the user needs to establish a link to a certain channel of the hardware by writing to the sysfs attribute add_link. And this is when minor_id is being used to create a new device that will show up in /dev. See store_add_link() function of the core module. regards, Chris > > thanks, > > greg k-h _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
