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SubjectRe: [PATCH 1/2] input: make serio_register_driver() return error code
Date
On Wednesday 08 November 2006 07:36, Akinobu Mita wrote:
>
> 2) driver_register() failure by kseriod.
>
> This failure cannot be checked by serio_register_driver().
> But it is necessary to prevent serio_unregister_driver() from
> trying to call driver_unregister() with not registered driver
> by adding flag to serio driver indicating whether registration is
> complete.
>

Hi Akinobu,

I think I found a way to handle all errors when registering serio driver.
What do you think about the patch below?

--
Dmitry

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
---

drivers/input/serio/serio.c | 109 ++++++++++++++++++++++++++++++--------------
include/linux/serio.h | 7 --
2 files changed, 76 insertions(+), 40 deletions(-)

Index: work/drivers/input/serio/serio.c
===================================================================
--- work.orig/drivers/input/serio/serio.c
+++ work/drivers/input/serio/serio.c
@@ -44,7 +44,7 @@ EXPORT_SYMBOL(serio_interrupt);
EXPORT_SYMBOL(__serio_register_port);
EXPORT_SYMBOL(serio_unregister_port);
EXPORT_SYMBOL(serio_unregister_child_port);
-EXPORT_SYMBOL(__serio_register_driver);
+EXPORT_SYMBOL(serio_register_driver);
EXPORT_SYMBOL(serio_unregister_driver);
EXPORT_SYMBOL(serio_open);
EXPORT_SYMBOL(serio_close);
@@ -61,10 +61,10 @@ static LIST_HEAD(serio_list);

static struct bus_type serio_bus;

-static void serio_add_driver(struct serio_driver *drv);
static void serio_add_port(struct serio *serio);
static void serio_reconnect_port(struct serio *serio);
static void serio_disconnect_port(struct serio *serio);
+static void serio_attach_driver(struct serio_driver *drv);

static int serio_connect_driver(struct serio *serio, struct serio_driver *drv)
{
@@ -168,10 +168,10 @@ static void serio_find_driver(struct ser
*/

enum serio_event_type {
- SERIO_RESCAN,
- SERIO_RECONNECT,
+ SERIO_RESCAN_PORT,
+ SERIO_RECONNECT_PORT,
SERIO_REGISTER_PORT,
- SERIO_REGISTER_DRIVER,
+ SERIO_ATTACH_DRIVER,
};

struct serio_event {
@@ -186,11 +186,12 @@ static LIST_HEAD(serio_event_list);
static DECLARE_WAIT_QUEUE_HEAD(serio_wait);
static struct task_struct *serio_task;

-static void serio_queue_event(void *object, struct module *owner,
- enum serio_event_type event_type)
+static int serio_queue_event(void *object, struct module *owner,
+ enum serio_event_type event_type)
{
unsigned long flags;
struct serio_event *event;
+ int retval = 0;

spin_lock_irqsave(&serio_event_lock, flags);

@@ -209,24 +210,34 @@ static void serio_queue_event(void *obje
}
}

- if ((event = kmalloc(sizeof(struct serio_event), GFP_ATOMIC))) {
- if (!try_module_get(owner)) {
- printk(KERN_WARNING "serio: Can't get module reference, dropping event %d\n", event_type);
- kfree(event);
- goto out;
- }
-
- event->type = event_type;
- event->object = object;
- event->owner = owner;
+ event = kmalloc(sizeof(struct serio_event), GFP_ATOMIC);
+ if (!event) {
+ printk(KERN_ERR
+ "serio: Not enough memory to queue event %d\n",
+ event_type);
+ retval = -ENOMEM;
+ goto out;
+ }

- list_add_tail(&event->node, &serio_event_list);
- wake_up(&serio_wait);
- } else {
- printk(KERN_ERR "serio: Not enough memory to queue event %d\n", event_type);
+ if (!try_module_get(owner)) {
+ printk(KERN_WARNING
+ "serio: Can't get module reference, dropping event %d\n",
+ event_type);
+ kfree(event);
+ retval = -EINVAL;
+ goto out;
}
+
+ event->type = event_type;
+ event->object = object;
+ event->owner = owner;
+
+ list_add_tail(&event->node, &serio_event_list);
+ wake_up(&serio_wait);
+
out:
spin_unlock_irqrestore(&serio_event_lock, flags);
+ return retval;
}

static void serio_free_event(struct serio_event *event)
@@ -304,17 +315,17 @@ static void serio_handle_event(void)
serio_add_port(event->object);
break;

- case SERIO_RECONNECT:
+ case SERIO_RECONNECT_PORT:
serio_reconnect_port(event->object);
break;

- case SERIO_RESCAN:
+ case SERIO_RESCAN_PORT:
serio_disconnect_port(event->object);
serio_find_driver(event->object);
break;

- case SERIO_REGISTER_DRIVER:
- serio_add_driver(event->object);
+ case SERIO_ATTACH_DRIVER:
+ serio_attach_driver(event->object);
break;

default:
@@ -666,12 +677,12 @@ static void serio_disconnect_port(struct

void serio_rescan(struct serio *serio)
{
- serio_queue_event(serio, NULL, SERIO_RESCAN);
+ serio_queue_event(serio, NULL, SERIO_RESCAN_PORT);
}

void serio_reconnect(struct serio *serio)
{
- serio_queue_event(serio, NULL, SERIO_RECONNECT);
+ serio_queue_event(serio, NULL, SERIO_RECONNECT_PORT);
}

/*
@@ -766,22 +777,52 @@ static int serio_driver_remove(struct de
return 0;
}

-static void serio_add_driver(struct serio_driver *drv)
+static void serio_attach_driver(struct serio_driver *drv)
{
int error;

- error = driver_register(&drv->driver);
+ error = driver_attach(&drv->driver);
if (error)
- printk(KERN_ERR
- "serio: driver_register() failed for %s, error: %d\n",
- drv->driver.name, error);
+ printk(KERN_WARNING
+ "serio: driver_attach() failed with error %d\n",
+ error);
}

-void __serio_register_driver(struct serio_driver *drv, struct module *owner)
+int serio_register_driver(struct serio_driver *drv)
{
+ int manual_bind = drv->manual_bind;
+ int error;
+
drv->driver.bus = &serio_bus;

- serio_queue_event(drv, owner, SERIO_REGISTER_DRIVER);
+ /*
+ * Temporarily disable automatic binding because probing
+ * takes long time and we are better off doing it in kseriod
+ */
+ drv->manual_bind = 1;
+
+ error = driver_register(&drv->driver);
+ if (error) {
+ printk(KERN_ERR
+ "serio: driver_register() failed for %s, error: %d\n",
+ drv->driver.name, error);
+ return error;
+ }
+
+ /*
+ * Restore original bind mode and let kseriod bind the
+ * driver to free ports
+ */
+ if (!manual_bind) {
+ drv->manual_bind = 0;
+ error = serio_queue_event(drv, NULL, SERIO_ATTACH_DRIVER);
+ if (error) {
+ driver_unregister(&drv->driver);
+ return error;
+ }
+ }
+
+ return 0;
}

void serio_unregister_driver(struct serio_driver *drv)
Index: work/include/linux/serio.h
===================================================================
--- work.orig/include/linux/serio.h
+++ work/include/linux/serio.h
@@ -86,12 +86,7 @@ static inline void serio_register_port(s
void serio_unregister_port(struct serio *serio);
void serio_unregister_child_port(struct serio *serio);

-void __serio_register_driver(struct serio_driver *drv, struct module *owner);
-static inline void serio_register_driver(struct serio_driver *drv)
-{
- __serio_register_driver(drv, THIS_MODULE);
-}
-
+int serio_register_driver(struct serio_driver *drv);
void serio_unregister_driver(struct serio_driver *drv);

static inline int serio_write(struct serio *serio, unsigned char data)
-
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