[PATCH] ppdev: check before attaching port

[Sudip Mukherjee]

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 
Signed-off-by: Sudip Mukherjee 
---
 drivers/char/ppdev.c | 23 +--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/drivers/char/ppdev.c b/drivers/char/ppdev.c
index 6af1ce0..b30d68c 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 unsigned int pp_poll(struct file *file, poll_table 
*wait)
 
 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)
-- 
1.9.1

[PATCH] ppdev: check before attaching port

[Sudip Mukherjee]

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 
Signed-off-by: Sudip Mukherjee 
---
 drivers/char/ppdev.c | 23 +--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/drivers/char/ppdev.c b/drivers/char/ppdev.c
index 6af1ce0..b30d68c 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 unsigned int pp_poll(struct file *file, poll_table 
*wait)
 
 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)
-- 
1.9.1