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[IRDA]: Switching to a workqueue for the SIR work
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Since sir_kthread.c pretty much duplicates the workqueue
functionality, we'd better switch.  The SIR fsm has been merged into
sir_dev.c and thus sir_kthread.c is deleted.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Samuel Ortiz <samuel.ortiz@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Christoph Hellwig authored and David S. Miller committed May 9, 2006
1 parent d94c77b commit 788252e
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Showing 4 changed files with 314 additions and 524 deletions.
2 changes: 1 addition & 1 deletion drivers/net/irda/Makefile
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Original file line number Diff line number Diff line change
Expand Up @@ -46,4 +46,4 @@ obj-$(CONFIG_MA600_DONGLE) += ma600-sir.o
obj-$(CONFIG_TOIM3232_DONGLE) += toim3232-sir.o

# The SIR helper module
sir-dev-objs := sir_dev.o sir_dongle.o sir_kthread.o
sir-dev-objs := sir_dev.o sir_dongle.o
13 changes: 2 additions & 11 deletions drivers/net/irda/sir-dev.h
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Original file line number Diff line number Diff line change
Expand Up @@ -15,23 +15,14 @@
#define IRDA_SIR_H

#include <linux/netdevice.h>
#include <linux/workqueue.h>

#include <net/irda/irda.h>
#include <net/irda/irda_device.h> // iobuff_t

/* FIXME: unify irda_request with sir_fsm! */

struct irda_request {
struct list_head lh_request;
unsigned long pending;
void (*func)(void *);
void *data;
struct timer_list timer;
};

struct sir_fsm {
struct semaphore sem;
struct irda_request rq;
struct work_struct work;
unsigned state, substate;
int param;
int result;
Expand Down
315 changes: 311 additions & 4 deletions drivers/net/irda/sir_dev.c
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Original file line number Diff line number Diff line change
Expand Up @@ -23,6 +23,298 @@

#include "sir-dev.h"


static struct workqueue_struct *irda_sir_wq;

/* STATE MACHINE */

/* substate handler of the config-fsm to handle the cases where we want
* to wait for transmit completion before changing the port configuration
*/

static int sirdev_tx_complete_fsm(struct sir_dev *dev)
{
struct sir_fsm *fsm = &dev->fsm;
unsigned next_state, delay;
unsigned bytes_left;

do {
next_state = fsm->substate; /* default: stay in current substate */
delay = 0;

switch(fsm->substate) {

case SIRDEV_STATE_WAIT_XMIT:
if (dev->drv->chars_in_buffer)
bytes_left = dev->drv->chars_in_buffer(dev);
else
bytes_left = 0;
if (!bytes_left) {
next_state = SIRDEV_STATE_WAIT_UNTIL_SENT;
break;
}

if (dev->speed > 115200)
delay = (bytes_left*8*10000) / (dev->speed/100);
else if (dev->speed > 0)
delay = (bytes_left*10*10000) / (dev->speed/100);
else
delay = 0;
/* expected delay (usec) until remaining bytes are sent */
if (delay < 100) {
udelay(delay);
delay = 0;
break;
}
/* sleep some longer delay (msec) */
delay = (delay+999) / 1000;
break;

case SIRDEV_STATE_WAIT_UNTIL_SENT:
/* block until underlaying hardware buffer are empty */
if (dev->drv->wait_until_sent)
dev->drv->wait_until_sent(dev);
next_state = SIRDEV_STATE_TX_DONE;
break;

case SIRDEV_STATE_TX_DONE:
return 0;

default:
IRDA_ERROR("%s - undefined state\n", __FUNCTION__);
return -EINVAL;
}
fsm->substate = next_state;
} while (delay == 0);
return delay;
}

/*
* Function sirdev_config_fsm
*
* State machine to handle the configuration of the device (and attached dongle, if any).
* This handler is scheduled for execution in kIrDAd context, so we can sleep.
* however, kIrDAd is shared by all sir_dev devices so we better don't sleep there too
* long. Instead, for longer delays we start a timer to reschedule us later.
* On entry, fsm->sem is always locked and the netdev xmit queue stopped.
* Both must be unlocked/restarted on completion - but only on final exit.
*/

static void sirdev_config_fsm(void *data)
{
struct sir_dev *dev = data;
struct sir_fsm *fsm = &dev->fsm;
int next_state;
int ret = -1;
unsigned delay;

IRDA_DEBUG(2, "%s(), <%ld>\n", __FUNCTION__, jiffies);

do {
IRDA_DEBUG(3, "%s - state=0x%04x / substate=0x%04x\n",
__FUNCTION__, fsm->state, fsm->substate);

next_state = fsm->state;
delay = 0;

switch(fsm->state) {

case SIRDEV_STATE_DONGLE_OPEN:
if (dev->dongle_drv != NULL) {
ret = sirdev_put_dongle(dev);
if (ret) {
fsm->result = -EINVAL;
next_state = SIRDEV_STATE_ERROR;
break;
}
}

/* Initialize dongle */
ret = sirdev_get_dongle(dev, fsm->param);
if (ret) {
fsm->result = ret;
next_state = SIRDEV_STATE_ERROR;
break;
}

/* Dongles are powered through the modem control lines which
* were just set during open. Before resetting, let's wait for
* the power to stabilize. This is what some dongle drivers did
* in open before, while others didn't - should be safe anyway.
*/

delay = 50;
fsm->substate = SIRDEV_STATE_DONGLE_RESET;
next_state = SIRDEV_STATE_DONGLE_RESET;

fsm->param = 9600;

break;

case SIRDEV_STATE_DONGLE_CLOSE:
/* shouldn't we just treat this as success=? */
if (dev->dongle_drv == NULL) {
fsm->result = -EINVAL;
next_state = SIRDEV_STATE_ERROR;
break;
}

ret = sirdev_put_dongle(dev);
if (ret) {
fsm->result = ret;
next_state = SIRDEV_STATE_ERROR;
break;
}
next_state = SIRDEV_STATE_DONE;
break;

case SIRDEV_STATE_SET_DTR_RTS:
ret = sirdev_set_dtr_rts(dev,
(fsm->param&0x02) ? TRUE : FALSE,
(fsm->param&0x01) ? TRUE : FALSE);
next_state = SIRDEV_STATE_DONE;
break;

case SIRDEV_STATE_SET_SPEED:
fsm->substate = SIRDEV_STATE_WAIT_XMIT;
next_state = SIRDEV_STATE_DONGLE_CHECK;
break;

case SIRDEV_STATE_DONGLE_CHECK:
ret = sirdev_tx_complete_fsm(dev);
if (ret < 0) {
fsm->result = ret;
next_state = SIRDEV_STATE_ERROR;
break;
}
if ((delay=ret) != 0)
break;

if (dev->dongle_drv) {
fsm->substate = SIRDEV_STATE_DONGLE_RESET;
next_state = SIRDEV_STATE_DONGLE_RESET;
}
else {
dev->speed = fsm->param;
next_state = SIRDEV_STATE_PORT_SPEED;
}
break;

case SIRDEV_STATE_DONGLE_RESET:
if (dev->dongle_drv->reset) {
ret = dev->dongle_drv->reset(dev);
if (ret < 0) {
fsm->result = ret;
next_state = SIRDEV_STATE_ERROR;
break;
}
}
else
ret = 0;
if ((delay=ret) == 0) {
/* set serial port according to dongle default speed */
if (dev->drv->set_speed)
dev->drv->set_speed(dev, dev->speed);
fsm->substate = SIRDEV_STATE_DONGLE_SPEED;
next_state = SIRDEV_STATE_DONGLE_SPEED;
}
break;

case SIRDEV_STATE_DONGLE_SPEED:
if (dev->dongle_drv->reset) {
ret = dev->dongle_drv->set_speed(dev, fsm->param);
if (ret < 0) {
fsm->result = ret;
next_state = SIRDEV_STATE_ERROR;
break;
}
}
else
ret = 0;
if ((delay=ret) == 0)
next_state = SIRDEV_STATE_PORT_SPEED;
break;

case SIRDEV_STATE_PORT_SPEED:
/* Finally we are ready to change the serial port speed */
if (dev->drv->set_speed)
dev->drv->set_speed(dev, dev->speed);
dev->new_speed = 0;
next_state = SIRDEV_STATE_DONE;
break;

case SIRDEV_STATE_DONE:
/* Signal network layer so it can send more frames */
netif_wake_queue(dev->netdev);
next_state = SIRDEV_STATE_COMPLETE;
break;

default:
IRDA_ERROR("%s - undefined state\n", __FUNCTION__);
fsm->result = -EINVAL;
/* fall thru */

case SIRDEV_STATE_ERROR:
IRDA_ERROR("%s - error: %d\n", __FUNCTION__, fsm->result);

#if 0 /* don't enable this before we have netdev->tx_timeout to recover */
netif_stop_queue(dev->netdev);
#else
netif_wake_queue(dev->netdev);
#endif
/* fall thru */

case SIRDEV_STATE_COMPLETE:
/* config change finished, so we are not busy any longer */
sirdev_enable_rx(dev);
up(&fsm->sem);
return;
}
fsm->state = next_state;
} while(!delay);

queue_delayed_work(irda_sir_wq, &fsm->work, msecs_to_jiffies(delay));
}

/* schedule some device configuration task for execution by kIrDAd
* on behalf of the above state machine.
* can be called from process or interrupt/tasklet context.
*/

int sirdev_schedule_request(struct sir_dev *dev, int initial_state, unsigned param)
{
struct sir_fsm *fsm = &dev->fsm;

IRDA_DEBUG(2, "%s - state=0x%04x / param=%u\n", __FUNCTION__, initial_state, param);

if (down_trylock(&fsm->sem)) {
if (in_interrupt() || in_atomic() || irqs_disabled()) {
IRDA_DEBUG(1, "%s(), state machine busy!\n", __FUNCTION__);
return -EWOULDBLOCK;
} else
down(&fsm->sem);
}

if (fsm->state == SIRDEV_STATE_DEAD) {
/* race with sirdev_close should never happen */
IRDA_ERROR("%s(), instance staled!\n", __FUNCTION__);
up(&fsm->sem);
return -ESTALE; /* or better EPIPE? */
}

netif_stop_queue(dev->netdev);
atomic_set(&dev->enable_rx, 0);

fsm->state = initial_state;
fsm->param = param;
fsm->result = 0;

INIT_WORK(&fsm->work, sirdev_config_fsm, dev);
queue_work(irda_sir_wq, &fsm->work);
return 0;
}


/***************************************************************************/

void sirdev_enable_rx(struct sir_dev *dev)
Expand Down Expand Up @@ -619,10 +911,6 @@ struct sir_dev * sirdev_get_instance(const struct sir_driver *drv, const char *n
spin_lock_init(&dev->tx_lock);
init_MUTEX(&dev->fsm.sem);

INIT_LIST_HEAD(&dev->fsm.rq.lh_request);
dev->fsm.rq.pending = 0;
init_timer(&dev->fsm.rq.timer);

dev->drv = drv;
dev->netdev = ndev;

Expand Down Expand Up @@ -682,3 +970,22 @@ int sirdev_put_instance(struct sir_dev *dev)
}
EXPORT_SYMBOL(sirdev_put_instance);

static int __init sir_wq_init(void)
{
irda_sir_wq = create_singlethread_workqueue("irda_sir_wq");
if (!irda_sir_wq)
return -ENOMEM;
return 0;
}

static void __exit sir_wq_exit(void)
{
destroy_workqueue(irda_sir_wq);
}

module_init(sir_wq_init);
module_exit(sir_wq_exit);

MODULE_AUTHOR("Martin Diehl <info@mdiehl.de>");
MODULE_DESCRIPTION("IrDA SIR core");
MODULE_LICENSE("GPL");
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