* [PATCH] esp: replace cli()/sti() with spin_lock_irqsave()/spin_unlock_irqrestore()
@ 2004-12-17 23:18 James Nelson
2004-12-18 1:21 ` Jan Dittmer
0 siblings, 1 reply; 3+ messages in thread
From: James Nelson @ 2004-12-17 23:18 UTC (permalink / raw)
To: kernel-janitors, linux-kernel; +Cc: akpm, James Nelson
This is an attempt to make the esp driver SMP-correct.
Compile tested.
Signed-off-by: James Nelson <james4765@gmail.com>
diff -urN --exclude='*~' linux-2.6.10-rc3-mm1-original/drivers/char/esp.c linux-2.6.10-rc3-mm1/drivers/char/esp.c
--- linux-2.6.10-rc3-mm1-original/drivers/char/esp.c 2004-12-03 16:52:13.000000000 -0500
+++ linux-2.6.10-rc3-mm1/drivers/char/esp.c 2004-12-17 18:11:31.275037730 -0500
@@ -84,6 +84,8 @@
static unsigned int rx_timeout = ESP_RX_TMOUT;
static unsigned int pio_threshold = ESP_PIO_THRESHOLD;
+static spinlock_t esp_lock = SPIN_LOCK_UNLOCKED;
+
MODULE_LICENSE("GPL");
module_param_array(irq, int, NULL, 0);
@@ -212,14 +214,14 @@
if (serial_paranoia_check(info, tty->name, "rs_stop"))
return;
- save_flags(flags); cli();
+ spin_lock_irqsave(&esp_lock, flags);
if (info->IER & UART_IER_THRI) {
info->IER &= ~UART_IER_THRI;
serial_out(info, UART_ESI_CMD1, ESI_SET_SRV_MASK);
serial_out(info, UART_ESI_CMD2, info->IER);
}
- restore_flags(flags);
+ spin_unlock_irqrestore(&esp_lock, flags);
}
static void rs_start(struct tty_struct *tty)
@@ -230,13 +232,13 @@
if (serial_paranoia_check(info, tty->name, "rs_start"))
return;
- save_flags(flags); cli();
+ spin_lock_irqsave(&esp_lock, flags);
if (info->xmit_cnt && info->xmit_buf && !(info->IER & UART_IER_THRI)) {
info->IER |= UART_IER_THRI;
serial_out(info, UART_ESI_CMD1, ESI_SET_SRV_MASK);
serial_out(info, UART_ESI_CMD2, info->IER);
}
- restore_flags(flags);
+ spin_unlock_irqrestore(&esp_lock, flags);
}
/*
@@ -311,7 +313,7 @@
return;
}
- sti();
+ spin_unlock_irq(&esp_lock);
status_mask = (info->read_status_mask >> 2) & 0x07;
@@ -329,7 +331,7 @@
(serial_in(info, UART_ESI_RWS) >> 3) & status_mask;
}
- cli();
+ spin_lock_irq(&esp_lock);
/* make sure everything is still ok since interrupts were enabled */
tty = info->tty;
@@ -478,7 +480,7 @@
info->xmit_tail = (info->xmit_tail + space_avail) &
(ESP_XMIT_SIZE - 1);
- sti();
+ spin_unlock_irq(&esp_lock);
for (i = 0; i < space_avail - 1; i += 2) {
outw(*((unsigned short *)(pio_buf->data + i)),
@@ -489,7 +491,7 @@
serial_out(info, UART_ESI_TX,
pio_buf->data[space_avail - 1]);
- cli();
+ spin_lock_irq(&esp_lock);
if (info->xmit_cnt) {
serial_out(info, UART_ESI_CMD1, ESI_NO_COMMAND);
@@ -654,10 +656,10 @@
err_status = 0;
scratch = serial_in(info, UART_ESI_SID);
- cli();
+ spin_lock_irq(&esp_lock);
if (!info->tty) {
- sti();
+ spin_unlock_irq(&esp_lock);
return IRQ_NONE;
}
@@ -740,7 +742,7 @@
#ifdef SERIAL_DEBUG_INTR
printk("end.\n");
#endif
- sti();
+ spin_unlock_irq(&esp_lock);
return IRQ_HANDLED;
}
@@ -859,7 +861,7 @@
int retval=0;
unsigned int num_chars;
- save_flags(flags); cli();
+ spin_lock_irqsave(&esp_lock, flags);
if (info->flags & ASYNC_INITIALIZED)
goto out;
@@ -973,7 +975,7 @@
info->flags |= ASYNC_INITIALIZED;
retval = 0;
-out: restore_flags(flags);
+out: spin_unlock_irqrestore(&esp_lock, flags);
return retval;
}
@@ -993,7 +995,7 @@
info->irq);
#endif
- save_flags(flags); cli(); /* Disable interrupts */
+ spin_lock_irqsave(&esp_lock, flags); /* Disable interrupts */
/*
* clear delta_msr_wait queue to avoid mem leaks: we may free the irq
@@ -1058,7 +1060,7 @@
set_bit(TTY_IO_ERROR, &info->tty->flags);
info->flags &= ~ASYNC_INITIALIZED;
- restore_flags(flags);
+ spin_unlock_irqrestore(&esp_lock, flags);
}
/*
@@ -1172,7 +1174,7 @@
if (I_IXOFF(info->tty))
flow1 |= 0x81;
- save_flags(flags); cli();
+ spin_lock_irqsave(&esp_lock, flags);
/* set baud */
serial_out(info, UART_ESI_CMD1, ESI_SET_BAUD);
serial_out(info, UART_ESI_CMD2, quot >> 8);
@@ -1219,7 +1221,7 @@
serial_out(info, UART_ESI_CMD2, info->config.flow_on >> 8);
serial_out(info, UART_ESI_CMD2, info->config.flow_on);
- restore_flags(flags);
+ spin_unlock_irqrestore(&esp_lock, flags);
}
static void rs_put_char(struct tty_struct *tty, unsigned char ch)
@@ -1233,7 +1235,7 @@
if (!tty || !info->xmit_buf)
return;
- save_flags(flags); cli();
+ spin_lock_irqsave(&esp_lock, flags);
if (info->xmit_cnt >= ESP_XMIT_SIZE - 1) {
restore_flags(flags);
return;
@@ -1242,7 +1244,7 @@
info->xmit_buf[info->xmit_head++] = ch;
info->xmit_head &= ESP_XMIT_SIZE-1;
info->xmit_cnt++;
- restore_flags(flags);
+ spin_unlock_irqrestore(&esp_lock, flags);
}
static void rs_flush_chars(struct tty_struct *tty)
@@ -1256,13 +1258,13 @@
if (info->xmit_cnt <= 0 || tty->stopped || !info->xmit_buf)
return;
- save_flags(flags); cli();
+ spin_lock_irqsave(&esp_lock, flags);
if (!(info->IER & UART_IER_THRI)) {
info->IER |= UART_IER_THRI;
serial_out(info, UART_ESI_CMD1, ESI_SET_SRV_MASK);
serial_out(info, UART_ESI_CMD2, info->IER);
}
- restore_flags(flags);
+ spin_unlock_irqrestore(&esp_lock, flags);
}
static int rs_write(struct tty_struct * tty,
@@ -1305,7 +1307,7 @@
ret += c;
}
- save_flags(flags); cli();
+ spin_lock_irqsave(&esp_lock, flags);
if (info->xmit_cnt && !tty->stopped && !(info->IER & UART_IER_THRI)) {
info->IER |= UART_IER_THRI;
@@ -1313,7 +1315,7 @@
serial_out(info, UART_ESI_CMD2, info->IER);
}
- restore_flags(flags);
+ spin_unlock_irqrestore(&esp_lock, flags);
return ret;
}
@@ -1345,9 +1347,9 @@
if (serial_paranoia_check(info, tty->name, "rs_flush_buffer"))
return;
- cli();
+ spin_lock_irq(&esp_lock);
info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
- sti();
+ spin_unlock_irq(&esp_lock);
tty_wakeup(tty);
}
@@ -1372,13 +1374,13 @@
if (serial_paranoia_check(info, tty->name, "rs_throttle"))
return;
- cli();
+ spin_lock_irq(&esp_lock);
info->IER &= ~UART_IER_RDI;
serial_out(info, UART_ESI_CMD1, ESI_SET_SRV_MASK);
serial_out(info, UART_ESI_CMD2, info->IER);
serial_out(info, UART_ESI_CMD1, ESI_SET_RX_TIMEOUT);
serial_out(info, UART_ESI_CMD2, 0x00);
- sti();
+ spin_unlock_irq(&esp_lock);
}
static void rs_unthrottle(struct tty_struct * tty)
@@ -1394,13 +1396,13 @@
if (serial_paranoia_check(info, tty->name, "rs_unthrottle"))
return;
- cli();
+ spin_lock_irq(&esp_lock);
info->IER |= UART_IER_RDI;
serial_out(info, UART_ESI_CMD1, ESI_SET_SRV_MASK);
serial_out(info, UART_ESI_CMD2, info->IER);
serial_out(info, UART_ESI_CMD1, ESI_SET_RX_TIMEOUT);
serial_out(info, UART_ESI_CMD2, info->config.rx_timeout);
- sti();
+ spin_unlock_irq(&esp_lock);
}
/*
@@ -1654,13 +1656,13 @@
info->config.flow_off = new_config.flow_off;
info->config.flow_on = new_config.flow_on;
- save_flags(flags); cli();
+ spin_lock_irqsave(&esp_lock, flags);
serial_out(info, UART_ESI_CMD1, ESI_SET_FLOW_LVL);
serial_out(info, UART_ESI_CMD2, new_config.flow_off >> 8);
serial_out(info, UART_ESI_CMD2, new_config.flow_off);
serial_out(info, UART_ESI_CMD2, new_config.flow_on >> 8);
serial_out(info, UART_ESI_CMD2, new_config.flow_on);
- restore_flags(flags);
+ spin_unlock_irqrestore(&esp_lock, flags);
}
if ((new_config.rx_trigger != info->config.rx_trigger) ||
@@ -1669,7 +1671,7 @@
info->config.rx_trigger = new_config.rx_trigger;
info->config.tx_trigger = new_config.tx_trigger;
- save_flags(flags); cli();
+ spin_lock_irqsave(&esp_lock, flags);
serial_out(info, UART_ESI_CMD1, ESI_SET_TRIGGER);
serial_out(info, UART_ESI_CMD2,
new_config.rx_trigger >> 8);
@@ -1677,14 +1679,14 @@
serial_out(info, UART_ESI_CMD2,
new_config.tx_trigger >> 8);
serial_out(info, UART_ESI_CMD2, new_config.tx_trigger);
- restore_flags(flags);
+ spin_unlock_irqrestore(&esp_lock, flags);
}
if (new_config.rx_timeout != info->config.rx_timeout) {
unsigned long flags;
info->config.rx_timeout = new_config.rx_timeout;
- save_flags(flags); cli();
+ spin_lock_irqsave(&esp_lock, flags);
if (info->IER & UART_IER_RDI) {
serial_out(info, UART_ESI_CMD1,
@@ -1693,7 +1695,7 @@
new_config.rx_timeout);
}
- restore_flags(flags);
+ spin_unlock_irqrestore(&esp_lock, flags);
}
if (!(info->flags & ASYNC_INITIALIZED))
@@ -1717,10 +1719,10 @@
unsigned char status;
unsigned int result;
- cli();
+ spin_lock_irq(&esp_lock);
serial_out(info, UART_ESI_CMD1, ESI_GET_UART_STAT);
status = serial_in(info, UART_ESI_STAT1);
- sti();
+ spin_unlock_irq(&esp_lock);
result = ((status & UART_LSR_TEMT) ? TIOCSER_TEMT : 0);
return put_user(result,value);
}
@@ -1737,10 +1739,10 @@
return -EIO;
control = info->MCR;
- cli();
+ spin_lock_irq(&esp_lock);
serial_out(info, UART_ESI_CMD1, ESI_GET_UART_STAT);
status = serial_in(info, UART_ESI_STAT2);
- sti();
+ spin_unlock_irq(&esp_lock);
return ((control & UART_MCR_RTS) ? TIOCM_RTS : 0)
| ((control & UART_MCR_DTR) ? TIOCM_DTR : 0)
| ((status & UART_MSR_DCD) ? TIOCM_CAR : 0)
@@ -1759,7 +1761,7 @@
if (tty->flags & (1 << TTY_IO_ERROR))
return -EIO;
- cli();
+ spin_lock_irq(&esp_lock);
if (set & TIOCM_RTS)
info->MCR |= UART_MCR_RTS;
@@ -1774,7 +1776,7 @@
serial_out(info, UART_ESI_CMD1, ESI_WRITE_UART);
serial_out(info, UART_ESI_CMD2, UART_MCR);
serial_out(info, UART_ESI_CMD2, info->MCR);
- sti();
+ spin_unlock_irq(&esp_lock);
return 0;
}
@@ -1789,7 +1791,7 @@
if (serial_paranoia_check(info, tty->name, "esp_break"))
return;
- save_flags(flags); cli();
+ spin_lock_irqsave(&esp_lock, flags);
if (break_state == -1) {
serial_out(info, UART_ESI_CMD1, ESI_ISSUE_BREAK);
serial_out(info, UART_ESI_CMD2, 0x01);
@@ -1799,7 +1801,7 @@
serial_out(info, UART_ESI_CMD1, ESI_ISSUE_BREAK);
serial_out(info, UART_ESI_CMD2, 0x00);
}
- restore_flags(flags);
+ spin_unlock_irqrestore(&esp_lock, flags);
}
static int rs_ioctl(struct tty_struct *tty, struct file * file,
@@ -1849,17 +1851,17 @@
* Caller should use TIOCGICOUNT to see which one it was
*/
case TIOCMIWAIT:
- cli();
+ spin_lock_irq(&esp_lock);
cprev = info->icount; /* note the counters on entry */
- sti();
+ spin_unlock_irq(&esp_lock);
while (1) {
interruptible_sleep_on(&info->delta_msr_wait);
/* see if a signal did it */
if (signal_pending(current))
return -ERESTARTSYS;
- cli();
+ spin_lock_irq(&esp_lock);
cnow = info->icount; /* atomic copy */
- sti();
+ spin_unlock_irq(&esp_lock);
if (cnow.rng == cprev.rng &&
cnow.dsr == cprev.dsr &&
cnow.dcd == cprev.dcd &&
@@ -1886,9 +1888,9 @@
* RI where only 0->1 is counted.
*/
case TIOCGICOUNT:
- cli();
+ spin_lock_irq(&esp_lock);
cnow = info->icount;
- sti();
+ spin_unlock_irq(&esp_lock);
p_cuser = argp;
if (put_user(cnow.cts, &p_cuser->cts) ||
put_user(cnow.dsr, &p_cuser->dsr) ||
@@ -1923,22 +1925,22 @@
if ((old_termios->c_cflag & CBAUD) &&
!(tty->termios->c_cflag & CBAUD)) {
info->MCR &= ~(UART_MCR_DTR|UART_MCR_RTS);
- cli();
+ spin_lock_irq(&esp_lock);
serial_out(info, UART_ESI_CMD1, ESI_WRITE_UART);
serial_out(info, UART_ESI_CMD2, UART_MCR);
serial_out(info, UART_ESI_CMD2, info->MCR);
- sti();
+ spin_unlock_irq(&esp_lock);
}
/* Handle transition away from B0 status */
if (!(old_termios->c_cflag & CBAUD) &&
(tty->termios->c_cflag & CBAUD)) {
info->MCR |= (UART_MCR_DTR | UART_MCR_RTS);
- cli();
+ spin_lock_irq(&esp_lock);
serial_out(info, UART_ESI_CMD1, ESI_WRITE_UART);
serial_out(info, UART_ESI_CMD2, UART_MCR);
serial_out(info, UART_ESI_CMD2, info->MCR);
- sti();
+ spin_unlock_irq(&esp_lock);
}
/* Handle turning of CRTSCTS */
@@ -1978,7 +1980,7 @@
if (!info || serial_paranoia_check(info, tty->name, "rs_close"))
return;
- save_flags(flags); cli();
+ spin_lock_irqsave(&esp_lock, flags);
if (tty_hung_up_p(filp)) {
DBG_CNT("before DEC-hung");
@@ -2058,7 +2060,7 @@
info->flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CLOSING);
wake_up_interruptible(&info->close_wait);
out:
- restore_flags(flags);
+ spin_unlock_irqrestore(&esp_lock, flags);
}
static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
@@ -2076,7 +2078,7 @@
if (!char_time)
char_time = 1;
- save_flags(flags); cli();
+ spin_lock_irqsave(&esp_lock, flags);
serial_out(info, UART_ESI_CMD1, ESI_NO_COMMAND);
serial_out(info, UART_ESI_CMD1, ESI_GET_TX_AVAIL);
@@ -2094,7 +2096,7 @@
serial_out(info, UART_ESI_CMD1, ESI_GET_TX_AVAIL);
}
- restore_flags(flags);
+ spin_unlock_irqrestore(&esp_lock, flags);
set_current_state(TASK_RUNNING);
}
@@ -2174,15 +2176,13 @@
printk("block_til_ready before block: ttys%d, count = %d\n",
info->line, info->count);
#endif
- save_flags(flags);
- cli();
+ spin_lock_irqsave(&esp_lock, flags);
if (!tty_hung_up_p(filp))
info->count--;
- restore_flags(flags);
+ spin_unlock_irqrestore(&esp_lock, flags);
info->blocked_open++;
while (1) {
- save_flags(flags);
- cli();
+ spin_lock_irqsave(&esp_lock, flags);
if ((tty->termios->c_cflag & CBAUD)) {
unsigned int scratch;
@@ -2194,7 +2194,7 @@
serial_out(info, UART_ESI_CMD2,
scratch | UART_MCR_DTR | UART_MCR_RTS);
}
- restore_flags(flags);
+ spin_unlock_irqrestore(&esp_lock, flags);
set_current_state(TASK_INTERRUPTIBLE);
if (tty_hung_up_p(filp) ||
!(info->flags & ASYNC_INITIALIZED)) {
@@ -2335,7 +2335,7 @@
if (!request_region(info->port, REGION_SIZE, "esp serial"))
return -EIO;
- save_flags(flags); cli();
+ spin_lock_irqsave(&esp_lock, flags);
/*
* Check for ESP card
@@ -2372,7 +2372,7 @@
if (!port_detected)
release_region(info->port, REGION_SIZE);
- restore_flags(flags);
+ spin_unlock_irqrestore(&esp_lock, flags);
return (port_detected);
}
@@ -2569,12 +2569,11 @@
struct esp_pio_buffer *pio_buf;
/* printk("Unloading %s: version %s\n", serial_name, serial_version); */
- save_flags(flags);
- cli();
+ spin_lock_irqsave(&esp_lock, flags);
if ((e1 = tty_unregister_driver(esp_driver)))
printk("SERIAL: failed to unregister serial driver (%d)\n",
e1);
- restore_flags(flags);
+ spin_unlock_irqrestore(&esp_lock, flags);
put_tty_driver(esp_driver);
while (ports) {
diff -urN --exclude='*~' linux-2.6.10-rc3-mm1-original/drivers/char/Kconfig linux-2.6.10-rc3-mm1/drivers/char/Kconfig
--- linux-2.6.10-rc3-mm1-original/drivers/char/Kconfig 2004-12-03 16:52:14.000000000 -0500
+++ linux-2.6.10-rc3-mm1/drivers/char/Kconfig 2004-12-17 17:43:44.872008096 -0500
@@ -170,7 +170,7 @@
config ESPSERIAL
tristate "Hayes ESP serial port support"
- depends on SERIAL_NONSTANDARD && ISA && BROKEN_ON_SMP
+ depends on SERIAL_NONSTANDARD && ISA
help
This is a driver which supports Hayes ESP serial ports. Both single
port cards and multiport cards are supported. Make sure to read
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] esp: replace cli()/sti() with spin_lock_irqsave()/spin_unlock_irqrestore()
2004-12-17 23:18 [PATCH] esp: replace cli()/sti() with spin_lock_irqsave()/spin_unlock_irqrestore() James Nelson
@ 2004-12-18 1:21 ` Jan Dittmer
2004-12-18 3:46 ` Jim Nelson
0 siblings, 1 reply; 3+ messages in thread
From: Jan Dittmer @ 2004-12-18 1:21 UTC (permalink / raw)
To: James Nelson; +Cc: kernel-janitors, linux-kernel, akpm
James Nelson wrote:
> This is an attempt to make the esp driver SMP-correct.
You're trying to protect the info data, correct? Could you please
add a comment to the locks which data structures need to be
protected by them?!
Just blindly replacing cli/sti with spin_(un)lock doesn't make it
SMP save.
> diff -urN --exclude='*~' linux-2.6.10-rc3-mm1-original/drivers/char/esp.c linux-2.6.10-rc3-mm1/drivers/char/esp.c
> --- linux-2.6.10-rc3-mm1-original/drivers/char/esp.c 2004-12-03 16:52:13.000000000 -0500
> +++ linux-2.6.10-rc3-mm1/drivers/char/esp.c 2004-12-17 18:11:31.275037730 -0500
> @@ -212,14 +214,14 @@
> if (serial_paranoia_check(info, tty->name, "rs_stop"))
> return;
>
> - save_flags(flags); cli();
> + spin_lock_irqsave(&esp_lock, flags);
info can change between return and lock
> if (info->IER & UART_IER_THRI) {
> info->IER &= ~UART_IER_THRI;
> serial_out(info, UART_ESI_CMD1, ESI_SET_SRV_MASK);
> serial_out(info, UART_ESI_CMD2, info->IER);
> }
>
> - restore_flags(flags);
> + spin_unlock_irqrestore(&esp_lock, flags);
> }
>
> static void rs_start(struct tty_struct *tty)
> @@ -230,13 +232,13 @@
> if (serial_paranoia_check(info, tty->name, "rs_start"))
> return;
>
> - save_flags(flags); cli();
> + spin_lock_irqsave(&esp_lock, flags);
same here.
> if (info->xmit_cnt && info->xmit_buf && !(info->IER & UART_IER_THRI)) {
> info->IER |= UART_IER_THRI;
> serial_out(info, UART_ESI_CMD1, ESI_SET_SRV_MASK);
> serial_out(info, UART_ESI_CMD2, info->IER);
> }
> - restore_flags(flags);
> + spin_unlock_irqrestore(&esp_lock, flags);
> }
>
> /*
Didn't read the rest. Are you sure you didn't introduce a deadlock in
the interrupt handler? {transmit,receiver}_chars_{pio,dma} also try to take
the lock.
Jan
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] esp: replace cli()/sti() with spin_lock_irqsave()/spin_unlock_irqrestore()
2004-12-18 1:21 ` Jan Dittmer
@ 2004-12-18 3:46 ` Jim Nelson
0 siblings, 0 replies; 3+ messages in thread
From: Jim Nelson @ 2004-12-18 3:46 UTC (permalink / raw)
To: Jan Dittmer; +Cc: kernel-janitors, linux-kernel, akpm
Jan Dittmer wrote:
> James Nelson wrote:
>
>>This is an attempt to make the esp driver SMP-correct.
>
>
> You're trying to protect the info data, correct? Could you please
> add a comment to the locks which data structures need to be
> protected by them?!
> Just blindly replacing cli/sti with spin_(un)lock doesn't make it
> SMP save.
>
*sigh* Thought it wouldn't be that easy.
>
>>diff -urN --exclude='*~' linux-2.6.10-rc3-mm1-original/drivers/char/esp.c linux-2.6.10-rc3-mm1/drivers/char/esp.c
>>--- linux-2.6.10-rc3-mm1-original/drivers/char/esp.c 2004-12-03 16:52:13.000000000 -0500
>>+++ linux-2.6.10-rc3-mm1/drivers/char/esp.c 2004-12-17 18:11:31.275037730 -0500
>>@@ -212,14 +214,14 @@
>> if (serial_paranoia_check(info, tty->name, "rs_stop"))
>> return;
>>
>>- save_flags(flags); cli();
>>+ spin_lock_irqsave(&esp_lock, flags);
>
>
> info can change between return and lock
>
Okay. I see what you are talking about. I'll dig into it tomorrow (after some
sleep).
OTOH, this would have been SMP-incorrect even before cli()/sti() was dropped in 2.5 .
>
>> if (info->IER & UART_IER_THRI) {
>> info->IER &= ~UART_IER_THRI;
>> serial_out(info, UART_ESI_CMD1, ESI_SET_SRV_MASK);
>> serial_out(info, UART_ESI_CMD2, info->IER);
>> }
>>
>>- restore_flags(flags);
>>+ spin_unlock_irqrestore(&esp_lock, flags);
>> }
>>
>> static void rs_start(struct tty_struct *tty)
>>@@ -230,13 +232,13 @@
>> if (serial_paranoia_check(info, tty->name, "rs_start"))
>> return;
>>
>>- save_flags(flags); cli();
>>+ spin_lock_irqsave(&esp_lock, flags);
>
>
> same here.
>
>
>> if (info->xmit_cnt && info->xmit_buf && !(info->IER & UART_IER_THRI)) {
>> info->IER |= UART_IER_THRI;
>> serial_out(info, UART_ESI_CMD1, ESI_SET_SRV_MASK);
>> serial_out(info, UART_ESI_CMD2, info->IER);
>> }
>>- restore_flags(flags);
>>+ spin_unlock_irqrestore(&esp_lock, flags);
>> }
>>
>> /*
>
>
> Didn't read the rest. Are you sure you didn't introduce a deadlock in
> the interrupt handler? {transmit,receiver}_chars_{pio,dma} also try to take
> the lock.
>
Hm. I made the assumption (silly me) that the code was inherently SMP-correct,
and just needed the function calls replaced.
Live and learn.
Jim
> Jan
> -
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^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2004-12-18 3:46 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2004-12-17 23:18 [PATCH] esp: replace cli()/sti() with spin_lock_irqsave()/spin_unlock_irqrestore() James Nelson
2004-12-18 1:21 ` Jan Dittmer
2004-12-18 3:46 ` Jim Nelson
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