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ppdev: check before attaching port 

After parport starts using the device model, all pardevice drivers
should decide in their match_port callback function if they want to
attach with that particulatr port. ppdev has been converted to use the
new parport device-model code but pp_attach() tried to attach with all
the ports.
Create a new array of pointer and use that to remember the ports we
have attached. And use that information to skip attaching ports which
we have already attached.

Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Sudip Mukherjee 2016-11-12 21:22:12 +00:00 committed by Greg Kroah-Hartman
parent 826a4c6574
commit dd5c472a60
1 changed files with 21 additions and 2 deletions
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23
drivers/char/ppdev.c
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@ -86,6 +86,9 @@ struct pp_struct {
long default_inactivity;
};
/* should we use PARDEVICE_MAX here? */
static struct device *devices[PARPORT_MAX];
/* pp_struct.flags bitfields */
#define PP_CLAIMED (1<<0)
#define PP_EXCL (1<<1)
@ -789,13 +792,29 @@ static const struct file_operations pp_fops = {
static void pp_attach(struct parport *port)
{
device_create(ppdev_class, port->dev, MKDEV(PP_MAJOR, port->number),
NULL, "parport%d", port->number);
struct device *ret;
if (devices[port->number])
return;
ret = device_create(ppdev_class, port->dev,
MKDEV(PP_MAJOR, port->number), NULL,
"parport%d", port->number);
if (IS_ERR(ret)) {
pr_err("Failed to create device parport%d\n",
port->number);
return;
}
devices[port->number] = ret;
}
static void pp_detach(struct parport *port)
{
if (!devices[port->number])
return;
device_destroy(ppdev_class, MKDEV(PP_MAJOR, port->number));
devices[port->number] = NULL;
}
static int pp_probe(struct pardevice *par_dev)