This is a note to let you know that I've just added the patch titled
ppdev: check before attaching port
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ppdev-check-before-attaching-port.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From dd5c472a60e43549d789a17a8444513eec64bd7e Mon Sep 17 00:00:00 2001
From: Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx>
Date: Sat, 12 Nov 2016 21:22:12 +0000
Subject: ppdev: check before attaching port
From: Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx>
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@xxxxxxxxxx>
Signed-off-by: Sudip Mukherjee <sudip.mukherjee@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/char/ppdev.c | 23 +++++++++++++++++++++--
1 file changed, 21 insertions(+), 2 deletions(-)
--- 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_f
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)
Patches currently in stable-queue which might be from sudipm.mukherjee@xxxxxxxxx are
queue-4.9/ppdev-check-before-attaching-port.patch
queue-4.9/ppdev-fix-registering-same-device-name.patch