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Commit aa1190a2 authored by David Woodhouse's avatar David Woodhouse
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[PATCH] Remove cli() from R3964 line discipline. 

I did this ages ago but never submitted it because I never got round to
testing it. I still haven't tested it, but it ought to work, and the code
is definitely broken without it...
parent 86560be4
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Inline Side-by-side
Showing with 59 additions and 101 deletions
drivers/char/n_r3964.c
View file @ aa1190a2
......@@ -13,6 +13,12 @@
* L. Haag
*
* $Log: n_r3964.c,v $
* Revision 1.10 2001/03/18 13:02:24 dwmw2
* Fix timer usage, use spinlocks properly.
*
* Revision 1.9 2001/03/18 12:52:14 dwmw2
* Merge changes in 2.4.2
*
* Revision 1.8 2000/03/23 14:14:54 dwmw2
* Fix race in sleeping in r3964_read()
*
......@@ -110,8 +116,6 @@
#define TRACE_Q(fmt, arg...) /**/
#endif
static void on_timer_1(void*);
static void on_timer_2(void*);
static void add_tx_queue(struct r3964_info *, struct r3964_block_header *);
static void remove_from_tx_queue(struct r3964_info *pInfo, int error_code);
static void put_char(struct r3964_info *pInfo, unsigned char ch);
......@@ -120,7 +124,7 @@ static void retry_transmit(struct r3964_info *pInfo);
static void transmit_block(struct r3964_info *pInfo);
static void receive_char(struct r3964_info *pInfo, const unsigned char c);
static void receive_error(struct r3964_info *pInfo, const char flag);
static void on_timeout(struct r3964_info *pInfo);
static void on_timeout(unsigned long priv);
static int enable_signals(struct r3964_info *pInfo, pid_t pid, int arg);
static int read_telegram(struct r3964_info *pInfo, pid_t pid, unsigned char *buf);
static void add_msg(struct r3964_client_info *pClient, int msg_id, int arg,
......@@ -217,7 +221,7 @@ static int __init r3964_init(void)
{
int status;
printk ("r3964: Philips r3964 Driver $Revision: 1.8 $\n");
printk ("r3964: Philips r3964 Driver $Revision: 1.10 $\n");
/*
* Register the tty line discipline
......@@ -247,40 +251,11 @@ module_exit(r3964_exit);
* Protocol implementation routines
*************************************************************/
static void on_timer_1(void *arg)
{
struct r3964_info *pInfo = (struct r3964_info *)arg;
if(pInfo->count_down)
{
if(!--pInfo->count_down)
{
on_timeout(pInfo);
}
}
queue_task(&pInfo->bh_2, &tq_timer);
}
static void on_timer_2(void *arg)
{
struct r3964_info *pInfo = (struct r3964_info *)arg;
if(pInfo->count_down)
{
if(!--pInfo->count_down)
{
on_timeout(pInfo);
}
}
queue_task(&pInfo->bh_1, &tq_timer);
}
static void add_tx_queue(struct r3964_info *pInfo, struct r3964_block_header *pHeader)
{
unsigned long flags;
save_flags(flags);
cli();
spin_lock_irqsave(&pInfo->lock, flags);
pHeader->next = NULL;
......@@ -294,7 +269,7 @@ static void add_tx_queue(struct r3964_info *pInfo, struct r3964_block_header *pH
pInfo->tx_last = pHeader;
}
restore_flags(flags);
spin_unlock_irqrestore(&pInfo->lock, flags);
TRACE_Q("add_tx_queue %x, length %d, tx_first = %x",
(int)pHeader, pHeader->length, (int)pInfo->tx_first );
......@@ -337,8 +312,7 @@ static void remove_from_tx_queue(struct r3964_info *pInfo, int error_code)
wake_up_interruptible (&pInfo->read_wait);
}
save_flags(flags);
cli();
spin_lock_irqsave(&pInfo->lock, flags);
pInfo->tx_first = pHeader->next;
if(pInfo->tx_first==NULL)
......@@ -346,7 +320,7 @@ static void remove_from_tx_queue(struct r3964_info *pInfo, int error_code)
pInfo->tx_last = NULL;
}
restore_flags(flags);
spin_unlock_irqrestore(&pInfo->lock, flags);
kfree(pHeader);
TRACE_M("remove_from_tx_queue - kfree %x",(int)pHeader);
......@@ -359,8 +333,7 @@ static void add_rx_queue(struct r3964_info *pInfo, struct r3964_block_header *pH
{
unsigned long flags;
save_flags(flags);
cli();
spin_lock_irqsave(&pInfo->lock, flags);
pHeader->next = NULL;
......@@ -375,7 +348,7 @@ static void add_rx_queue(struct r3964_info *pInfo, struct r3964_block_header *pH
}
pInfo->blocks_in_rx_queue++;
restore_flags(flags);
spin_unlock_irqrestore(&pInfo->lock, flags);
TRACE_Q("add_rx_queue: %x, length = %d, rx_first = %x, count = %d",
(int)pHeader, pHeader->length,
......@@ -396,8 +369,7 @@ static void remove_from_rx_queue(struct r3964_info *pInfo,
TRACE_Q("remove_from_rx_queue: %x, length %d",
(int)pHeader, (int)pHeader->length );
save_flags(flags);
cli();
spin_lock_irqsave(&pInfo->lock, flags);
if(pInfo->rx_first == pHeader)
{
......@@ -430,7 +402,7 @@ static void remove_from_rx_queue(struct r3964_info *pInfo,
}
}
restore_flags(flags);
spin_unlock_irqrestore(&pInfo->lock, flags);
kfree(pHeader);
TRACE_M("remove_from_rx_queue - kfree %x",(int)pHeader);
......@@ -471,17 +443,16 @@ static void trigger_transmit(struct r3964_info *pInfo)
unsigned long flags;
save_flags(flags);
cli();
spin_lock_irqsave(&pInfo->lock, flags);
if((pInfo->state == R3964_IDLE) && (pInfo->tx_first!=NULL))
{
pInfo->state = R3964_TX_REQUEST;
pInfo->count_down = R3964_TO_QVZ;
pInfo->nRetry=0;
pInfo->flags &= ~R3964_ERROR;
mod_timer(&pInfo->tmr, jiffies + R3964_TO_QVZ);
restore_flags(flags);
spin_unlock_irqrestore(&pInfo->lock, flags);
TRACE_PS("trigger_transmit - sent STX");
......@@ -492,7 +463,7 @@ static void trigger_transmit(struct r3964_info *pInfo)
}
else
{
restore_flags(flags);
spin_unlock_irqrestore(&pInfo->lock, flags);
}
}
......@@ -506,8 +477,8 @@ static void retry_transmit(struct r3964_info *pInfo)
put_char(pInfo, STX);
flush(pInfo);
pInfo->state = R3964_TX_REQUEST;
pInfo->count_down = R3964_TO_QVZ;
pInfo->nRetry++;
mod_timer(&pInfo->tmr, jiffies + R3964_TO_QVZ);
}
else
{
......@@ -566,7 +537,7 @@ static void transmit_block(struct r3964_info *pInfo)
put_char(pInfo, pInfo->bcc);
}
pInfo->state = R3964_WAIT_FOR_TX_ACK;
pInfo->count_down = R3964_TO_QVZ;
mod_timer(&pInfo->tmr, jiffies + R3964_TO_QVZ);
}
flush(pInfo);
}
......@@ -601,8 +572,8 @@ static void on_receive_block(struct r3964_info *pInfo)
if(pInfo->nRetry<R3964_MAX_RETRIES)
{
pInfo->state=R3964_WAIT_FOR_RX_REPEAT;
pInfo->count_down = R3964_TO_RX_PANIC;
pInfo->nRetry++;
mod_timer(&pInfo->tmr, jiffies + R3964_TO_RX_PANIC);
}
else
{
......@@ -616,7 +587,7 @@ static void on_receive_block(struct r3964_info *pInfo)
/* received block; submit DLE: */
put_char(pInfo, DLE);
flush(pInfo);
pInfo->count_down=0;
del_timer_sync(&pInfo->tmr);
TRACE_PS(" rx success: got %d chars", length);
/* prepare struct r3964_block_header: */
......@@ -701,7 +672,7 @@ static void receive_char(struct r3964_info *pInfo, const unsigned char c)
TRACE_PE("TRANSMITTING - got illegal char");
pInfo->state = R3964_WAIT_ZVZ_BEFORE_TX_RETRY;
pInfo->count_down = R3964_TO_ZVZ;
mod_timer(&pInfo->tmr, jiffies + R3964_TO_ZVZ);
}
break;
case R3964_WAIT_FOR_TX_ACK:
......@@ -728,7 +699,7 @@ static void receive_char(struct r3964_info *pInfo, const unsigned char c)
{
TRACE_PE("IDLE - got STX but no space in rx_queue!");
pInfo->state=R3964_WAIT_FOR_RX_BUF;
pInfo->count_down = R3964_TO_NO_BUF;
mod_timer(&pInfo->tmr, R3964_TO_NO_BUF);
break;
}
start_receiving:
......@@ -738,7 +709,7 @@ static void receive_char(struct r3964_info *pInfo, const unsigned char c)
pInfo->last_rx = 0;
pInfo->flags &= ~R3964_ERROR;
pInfo->state=R3964_RECEIVING;
pInfo->count_down = R3964_TO_ZVZ;
mod_timer(&pInfo->tmr, R3964_TO_ZVZ);
pInfo->nRetry = 0;
put_char(pInfo, DLE);
flush(pInfo);
......@@ -765,7 +736,7 @@ static void receive_char(struct r3964_info *pInfo, const unsigned char c)
if(pInfo->flags & R3964_BCC)
{
pInfo->state = R3964_WAIT_FOR_BCC;
pInfo->count_down = R3964_TO_ZVZ;
mod_timer(&pInfo->tmr, R3964_TO_ZVZ);
}
else
{
......@@ -777,7 +748,7 @@ static void receive_char(struct r3964_info *pInfo, const unsigned char c)
pInfo->last_rx = c;
char_to_buf:
pInfo->rx_buf[pInfo->rx_position++] = c;
pInfo->count_down = R3964_TO_ZVZ;
mod_timer(&pInfo->tmr, R3964_TO_ZVZ);
}
}
/* else: overflow-msg? BUF_SIZE>MTU; should not happen? */
......@@ -818,8 +789,10 @@ static void receive_error(struct r3964_info *pInfo, const char flag)
}
}
static void on_timeout(struct r3964_info *pInfo)
static void on_timeout(unsigned long priv)
{
struct r3964_info *pInfo = (void *)priv;
switch(pInfo->state)
{
case R3964_TX_REQUEST:
......@@ -926,6 +899,7 @@ static int enable_signals(struct r3964_info *pInfo, pid_t pid, int arg)
return -ENOMEM;
TRACE_PS("add client %d to client list", pid);
spin_lock_init(&pClient->lock);
pClient->sig_flags=arg;
pClient->pid = pid;
pClient->next=pInfo->firstClient;
......@@ -989,8 +963,7 @@ static void add_msg(struct r3964_client_info *pClient, int msg_id, int arg,
return;
}
save_flags(flags);
cli();
spin_lock_irqsave(&pClient->lock, flags);
pMsg->msg_id = msg_id;
pMsg->arg = arg;
......@@ -1014,7 +987,7 @@ static void add_msg(struct r3964_client_info *pClient, int msg_id, int arg,
{
pBlock->locks++;
}
restore_flags(flags);
spin_unlock_irqrestore(&pClient->lock, flags);
}
else
{
......@@ -1049,8 +1022,7 @@ static struct r3964_message *remove_msg(struct r3964_info *pInfo,
if(pClient->first_msg)
{
save_flags(flags);
cli();
spin_lock_irqsave(&pClient->lock, flags);
pMsg = pClient->first_msg;
pClient->first_msg = pMsg->next;
......@@ -1065,7 +1037,7 @@ static struct r3964_message *remove_msg(struct r3964_info *pInfo,
remove_client_block(pInfo, pClient);
pClient->next_block_to_read = pMsg->block;
}
restore_flags(flags);
spin_unlock_irqrestore(&pClient->lock, flags);
}
return pMsg;
}
......@@ -1137,6 +1109,7 @@ static int r3964_open(struct tty_struct *tty)
return -ENOMEM;
}
spin_lock_init(&pInfo->lock);
pInfo->tty = tty;
init_waitqueue_head (&pInfo->read_wait);
pInfo->priority = R3964_MASTER;
......@@ -1149,26 +1122,13 @@ static int r3964_open(struct tty_struct *tty)
pInfo->firstClient=NULL;
pInfo->state=R3964_IDLE;
pInfo->flags = R3964_DEBUG;
pInfo->count_down = 0;
pInfo->nRetry = 0;
tty->disc_data = pInfo;
/*
* Add 'on_timer' to timer task queue
* (will be called from timer bh)
*/
INIT_LIST_HEAD(&pInfo->bh_1.list);
pInfo->bh_1.sync = 0;
pInfo->bh_1.routine = &on_timer_1;
pInfo->bh_1.data = pInfo;
INIT_LIST_HEAD(&pInfo->bh_2.list);
pInfo->bh_2.sync = 0;
pInfo->bh_2.routine = &on_timer_2;
pInfo->bh_2.data = pInfo;
queue_task(&pInfo->bh_1, &tq_timer);
INIT_LIST_HEAD(&pInfo->tmr.list);
pInfo->tmr.data = (unsigned long)pInfo;
pInfo->tmr.function = on_timeout;
return 0;
}
......@@ -1187,12 +1147,7 @@ static void r3964_close(struct tty_struct *tty)
* Make sure that our task queue isn't activated. If it
* is, take it out of the linked list.
*/
spin_lock_irqsave(&tqueue_lock, flags);
if (pInfo->bh_1.sync)
list_del(&pInfo->bh_1.list);
if (pInfo->bh_2.sync)
list_del(&pInfo->bh_2.list);
spin_unlock_irqrestore(&tqueue_lock, flags);
del_timer_sync(&pInfo->tmr);
/* Remove client-structs and message queues: */
pClient=pInfo->firstClient;
......@@ -1213,11 +1168,10 @@ static void r3964_close(struct tty_struct *tty)
pClient=pNext;
}
/* Remove jobs from tx_queue: */
save_flags(flags);
cli();
spin_lock_irqsave(&pInfo->lock, flags);
pHeader=pInfo->tx_first;
pInfo->tx_first=pInfo->tx_last=NULL;
restore_flags(flags);
spin_unlock_irqrestore(&pInfo->lock, flags);
while(pHeader)
{
......@@ -1430,10 +1384,9 @@ static unsigned int r3964_poll(struct tty_struct * tty, struct file * file,
if(pClient)
{
poll_wait(file, &pInfo->read_wait, wait);
save_flags(flags);
cli();
spin_lock_irqsave(&pInfo->lock, flags);
pMsg=pClient->first_msg;
restore_flags(flags);
spin_unlock_irqrestore(&pInfo->lock, flags);
if(pMsg)
result |= POLLIN | POLLRDNORM;
}
......
include/linux/n_r3964.h
View file @ aa1190a2
......@@ -13,6 +13,12 @@
* L. Haag
*
* $Log: r3964.h,v $
* Revision 1.3 2001/03/18 13:02:24 dwmw2
* Fix timer usage, use spinlocks properly.
*
* Revision 1.2 2001/03/18 12:53:15 dwmw2
* Merge changes in 2.4.2
*
* Revision 1.1.1.1 1998/10/13 16:43:14 dwmw2
* This'll screw the version control
*
......@@ -103,6 +109,7 @@ enum { R3964_IDLE,
struct r3964_message;
struct r3964_client_info {
spinlock_t lock;
pid_t pid;
unsigned int sig_flags;
......@@ -186,6 +193,7 @@ struct r3964_block_header
struct r3964_info {
spinlock_t lock;
struct tty_struct *tty;
unsigned char priority;
unsigned char *rx_buf; /* ring buffer */
......@@ -209,11 +217,8 @@ struct r3964_info {
unsigned int state;
unsigned int flags;
int count_down;
struct timer_list tmr;
int nRetry;
struct tq_struct bh_1;
struct tq_struct bh_2;
};
#endif
......
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