diff options
| author | Sudip Mukherjee <sudipm.mukherjee@gmail.com> | 2016-11-12 21:22:12 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-04-12 12:41:10 +0200 |
| commit | bf5202b58f61e8fe2dba5ec8cf5720225b1b9e4c (patch) | |
| tree | 6637ea724f7b3549cd5839b7511e9d7763568030 /drivers/char | |
| parent | 37feaf8095d352014555b82adb4a04609ca17d3f (diff) | |
ppdev: check before attaching port
commit dd5c472a60e43549d789a17a8444513eec64bd7e upstream.
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>
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/ppdev.c | 23 |
1 files changed, 21 insertions, 2 deletions
diff --git a/drivers/char/ppdev.c b/drivers/char/ppdev.c index 6af1ce04b3da..731e77caa807 100644 --- a/drivers/char/ppdev.c +++ b/drivers/char/ppdev.c @@ -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) |