#define HVC_MAJOR 229
#define HVC_MINOR 0
-#define TIMEOUT (10)
-
/*
* Wait this long per iteration while trying to push buffered data to the
* hypervisor before allowing the tty to complete a close operation.
/* Picks up late kicks after list walk but before schedule() */
static int hvc_kicked;
+static int hvc_init(void);
+
#ifdef CONFIG_MAGIC_SYSRQ
static int sysrq_pressed;
#endif
/*
* This value is used to assign a tty->index value to a hvc_struct based
* upon order of exposure via hvc_probe(), when we can not match it to
- * a console canidate registered with hvc_instantiate().
+ * a console candidate registered with hvc_instantiate().
*/
static int last_hvc = -1;
/*
- * Do not call this function with either the hvc_strucst_lock or the hvc_struct
+ * Do not call this function with either the hvc_structs_lock or the hvc_struct
* lock held. If successful, this function increments the kobject reference
* count against the target hvc_struct so it should be released when finished.
*/
-struct hvc_struct *hvc_get_by_index(int index)
+static struct hvc_struct *hvc_get_by_index(int index)
{
struct hvc_struct *hp;
unsigned long flags;
* hvc_console_setup() finds adapters.
*/
-void hvc_console_print(struct console *co, const char *b, unsigned count)
+static void hvc_console_print(struct console *co, const char *b,
+ unsigned count)
{
char c[N_OUTBUF] __ALIGNED__;
unsigned i = 0, n = 0;
if (index >= MAX_NR_HVC_CONSOLES)
return;
- /* This console adapter was removed so it is not useable. */
+ /* This console adapter was removed so it is not usable. */
if (vtermnos[index] < 0)
return;
return 0;
}
-struct console hvc_con_driver = {
+static struct console hvc_con_driver = {
.name = "hvc",
.write = hvc_console_print,
.device = hvc_console_device,
};
/*
- * Early console initialization. Preceeds driver initialization.
+ * Early console initialization. Precedes driver initialization.
*
* (1) we are first, and the user specified another driver
* -- index will remain -1
if (vtermnos[index] != -1)
return -1;
- /* make sure no no tty has been registerd in this index */
+ /* make sure no no tty has been registered in this index */
hp = hvc_get_by_index(index);
if (hp) {
kobject_put(&hp->kobj);
vtermnos[index] = vtermno;
cons_ops[index] = ops;
- /* reserve all indices upto and including this index */
+ /* reserve all indices up to and including this index */
if (last_hvc < index)
last_hvc = index;
return 0;
}
-EXPORT_SYMBOL(hvc_instantiate);
/* Wake the sleeping khvcd */
static void hvc_kick(void)
/*
* This is actually a contract between the driver and the tty layer outlining
- * how much write room the driver can guarentee will be sent OR BUFFERED. This
+ * how much write room the driver can guarantee will be sent OR BUFFERED. This
* driver MUST honor the return value.
*/
static int hvc_write_room(struct tty_struct *tty)
return hp->n_outbuf;
}
+/*
+ * timeout will vary between the MIN and MAX values defined here. By default
+ * and during console activity we will use a default MIN_TIMEOUT of 10. When
+ * the console is idle, we increase the timeout value on each pass through
+ * msleep until we reach the max. This may be noticeable as a brief (average
+ * one second) delay on the console before the console responds to input when
+ * there has been no input for some time.
+ */
+#define MIN_TIMEOUT (10)
+#define MAX_TIMEOUT (2000)
+static u32 timeout = MIN_TIMEOUT;
+
#define HVC_POLL_READ 0x00000001
#define HVC_POLL_WRITE 0x00000002
bail:
spin_unlock_irqrestore(&hp->lock, flags);
- if (read_total)
+ if (read_total) {
+ /* Activity is occurring, so reset the polling backoff value to
+ a minimum for performance. */
+ timeout = MIN_TIMEOUT;
+
tty_flip_buffer_push(tty);
-
+ }
+
return poll_mask;
}
* calling hvc_poll() who determines whether a console adapter support
* interrupts.
*/
-int khvcd(void *unused)
+static int khvcd(void *unused)
{
int poll_mask;
struct hvc_struct *hp;
+ set_freezable();
__set_current_state(TASK_RUNNING);
do {
poll_mask = 0;
if (!hvc_kicked) {
if (poll_mask == 0)
schedule();
- else
- msleep_interruptible(TIMEOUT);
+ else {
+ if (timeout < MAX_TIMEOUT)
+ timeout += (timeout >> 6) + 1;
+
+ msleep_interruptible(timeout);
+ }
}
__set_current_state(TASK_RUNNING);
} while (!kthread_should_stop());
struct hvc_struct *hp;
int i;
+ /* We wait until a driver actually comes along */
+ if (!hvc_driver) {
+ int err = hvc_init();
+ if (err)
+ return ERR_PTR(err);
+ }
+
hp = kmalloc(ALIGN(sizeof(*hp), sizeof(long)) + outbuf_size,
GFP_KERNEL);
if (!hp)
return hp;
}
-EXPORT_SYMBOL(hvc_alloc);
int __devexit hvc_remove(struct hvc_struct *hp)
{
/*
* We 'put' the instance that was grabbed when the kobject instance
- * was intialized using kobject_init(). Let the last holder of this
+ * was initialized using kobject_init(). Let the last holder of this
* kobject cause it to be removed, which will probably be the tty_hangup
* below.
*/
tty_hangup(tty);
return 0;
}
-EXPORT_SYMBOL(hvc_remove);
-/* Driver initialization. Follow console initialization. This is where the TTY
- * interfaces start to become available. */
-int __init hvc_init(void)
+/* Driver initialization: called as soon as someone uses hvc_alloc(). */
+static int hvc_init(void)
{
struct tty_driver *drv;
+ int err;
/* We need more than hvc_count adapters due to hotplug additions. */
drv = alloc_tty_driver(HVC_ALLOC_TTY_ADAPTERS);
- if (!drv)
- return -ENOMEM;
+ if (!drv) {
+ err = -ENOMEM;
+ goto out;
+ }
drv->owner = THIS_MODULE;
drv->driver_name = "hvc";
* added later. */
hvc_task = kthread_run(khvcd, NULL, "khvcd");
if (IS_ERR(hvc_task)) {
- panic("Couldn't create kthread for console.\n");
- put_tty_driver(drv);
- return -EIO;
+ printk(KERN_ERR "Couldn't create kthread for console.\n");
+ err = PTR_ERR(hvc_task);
+ goto put_tty;
}
- if (tty_register_driver(drv))
- panic("Couldn't register hvc console driver\n");
+ err = tty_register_driver(drv);
+ if (err) {
+ printk(KERN_ERR "Couldn't register hvc console driver\n");
+ goto stop_thread;
+ }
+ /* FIXME: This mb() seems completely random. Remove it. */
mb();
hvc_driver = drv;
return 0;
+
+put_tty:
+ put_tty_driver(hvc_driver);
+stop_thread:
+ kthread_stop(hvc_task);
+ hvc_task = NULL;
+out:
+ return err;
}
-module_init(hvc_init);
-/* This isn't particularily necessary due to this being a console driver
+/* This isn't particularly necessary due to this being a console driver
* but it is nice to be thorough.
*/
static void __exit hvc_exit(void)
{
- kthread_stop(hvc_task);
+ if (hvc_driver) {
+ kthread_stop(hvc_task);
- tty_unregister_driver(hvc_driver);
- /* return tty_struct instances allocated in hvc_init(). */
- put_tty_driver(hvc_driver);
- unregister_console(&hvc_con_driver);
+ tty_unregister_driver(hvc_driver);
+ /* return tty_struct instances allocated in hvc_init(). */
+ put_tty_driver(hvc_driver);
+ unregister_console(&hvc_con_driver);
+ }
}
module_exit(hvc_exit);
projects / linux-2.6-omap-h63xx.git / blobdiff