#include <linux/module.h>
#include <linux/serio.h>
#include <linux/errno.h>
-#include <linux/wait.h>
#include <linux/sched.h>
#include <linux/slab.h>
-#include <linux/kthread.h>
+#include <linux/workqueue.h>
#include <linux/mutex.h>
MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
/*
* serio_mutex protects entire serio subsystem and is taken every time
- * serio port or driver registrered or unregistered.
+ * serio port or driver registered or unregistered.
*/
static DEFINE_MUTEX(serio_mutex);
static DEFINE_SPINLOCK(serio_event_lock); /* protects serio_event_list */
static LIST_HEAD(serio_event_list);
-static DECLARE_WAIT_QUEUE_HEAD(serio_wait);
-static struct task_struct *serio_task;
-static int serio_queue_event(void *object, struct module *owner,
- enum serio_event_type event_type)
+static struct serio_event *serio_get_event(void)
{
+ struct serio_event *event = NULL;
unsigned long flags;
- struct serio_event *event;
- int retval = 0;
spin_lock_irqsave(&serio_event_lock, flags);
- /*
- * Scan event list for the other events for the same serio port,
- * starting with the most recent one. If event is the same we
- * do not need add new one. If event is of different type we
- * need to add this event and should not look further because
- * we need to preseve sequence of distinct events.
- */
- list_for_each_entry_reverse(event, &serio_event_list, node) {
- if (event->object == object) {
- if (event->type == event_type)
- goto out;
- break;
- }
- }
-
- event = kmalloc(sizeof(struct serio_event), GFP_ATOMIC);
- if (!event) {
- pr_err("Not enough memory to queue event %d\n", event_type);
- retval = -ENOMEM;
- goto out;
- }
-
- if (!try_module_get(owner)) {
- pr_warning("Can't get module reference, dropping event %d\n",
- event_type);
- kfree(event);
- retval = -EINVAL;
- goto out;
+ if (!list_empty(&serio_event_list)) {
+ event = list_first_entry(&serio_event_list,
+ struct serio_event, node);
+ list_del_init(&event->node);
}
- 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;
+ return event;
}
static void serio_free_event(struct serio_event *event)
kfree(event);
}
-static void serio_remove_duplicate_events(struct serio_event *event)
+static void serio_remove_duplicate_events(void *object,
+ enum serio_event_type type)
{
struct serio_event *e, *next;
unsigned long flags;
spin_lock_irqsave(&serio_event_lock, flags);
list_for_each_entry_safe(e, next, &serio_event_list, node) {
- if (event->object == e->object) {
+ if (object == e->object) {
/*
* If this event is of different type we should not
* look further - we only suppress duplicate events
* that were sent back-to-back.
*/
- if (event->type != e->type)
+ if (type != e->type)
break;
list_del_init(&e->node);
spin_unlock_irqrestore(&serio_event_lock, flags);
}
-
-static struct serio_event *serio_get_event(void)
-{
- struct serio_event *event = NULL;
- unsigned long flags;
-
- spin_lock_irqsave(&serio_event_lock, flags);
-
- if (!list_empty(&serio_event_list)) {
- event = list_first_entry(&serio_event_list,
- struct serio_event, node);
- list_del_init(&event->node);
- }
-
- spin_unlock_irqrestore(&serio_event_lock, flags);
- return event;
-}
-
-static void serio_handle_event(void)
+static void serio_handle_event(struct work_struct *work)
{
struct serio_event *event;
break;
}
- serio_remove_duplicate_events(event);
+ serio_remove_duplicate_events(event->object, event->type);
serio_free_event(event);
}
mutex_unlock(&serio_mutex);
}
+static DECLARE_WORK(serio_event_work, serio_handle_event);
+
+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);
+
+ /*
+ * Scan event list for the other events for the same serio port,
+ * starting with the most recent one. If event is the same we
+ * do not need add new one. If event is of different type we
+ * need to add this event and should not look further because
+ * we need to preseve sequence of distinct events.
+ */
+ list_for_each_entry_reverse(event, &serio_event_list, node) {
+ if (event->object == object) {
+ if (event->type == event_type)
+ goto out;
+ break;
+ }
+ }
+
+ event = kmalloc(sizeof(struct serio_event), GFP_ATOMIC);
+ if (!event) {
+ pr_err("Not enough memory to queue event %d\n", event_type);
+ retval = -ENOMEM;
+ goto out;
+ }
+
+ if (!try_module_get(owner)) {
+ pr_warning("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);
+ queue_work(system_long_wq, &serio_event_work);
+
+out:
+ spin_unlock_irqrestore(&serio_event_lock, flags);
+ return retval;
+}
+
/*
* Remove all events that have been submitted for a given
* object, be it serio port or driver.
return child;
}
-static int serio_thread(void *nothing)
-{
- do {
- serio_handle_event();
- wait_event_interruptible(serio_wait,
- kthread_should_stop() || !list_empty(&serio_event_list));
- } while (!kthread_should_stop());
-
- return 0;
-}
-
-
/*
* Serio port operations
*/
} else if (!strncmp(buf, "rescan", count)) {
serio_disconnect_port(serio);
serio_find_driver(serio);
+ serio_remove_duplicate_events(serio, SERIO_RESCAN_PORT);
} else if ((drv = driver_find(buf, &serio_bus)) != NULL) {
serio_disconnect_port(serio);
error = serio_bind_driver(serio, to_serio_driver(drv));
put_driver(drv);
+ serio_remove_duplicate_events(serio, SERIO_RESCAN_PORT);
} else {
error = -EINVAL;
}
return error;
}
- serio_task = kthread_run(serio_thread, NULL, "kseriod");
- if (IS_ERR(serio_task)) {
- bus_unregister(&serio_bus);
- error = PTR_ERR(serio_task);
- pr_err("Failed to start kseriod, error: %d\n", error);
- return error;
- }
-
return 0;
}
static void __exit serio_exit(void)
{
bus_unregister(&serio_bus);
- kthread_stop(serio_task);
+
+ /*
+ * There should not be any outstanding events but work may
+ * still be scheduled so simply cancel it.
+ */
+ cancel_work_sync(&serio_event_work);
}
subsys_initcall(serio_init);
projects / mv-sheeva.git / blobdiff