lkml.org 
[lkml]   [2002]   [Aug]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
Subject[PATCH 2.5] : ir252_ali_locking_fixes-3.diff
From
ir252_ali_locking_fixes-3.diff :
------------------------------
o [CORRECT] Remove all "save_flags(flags);cli();" in IrDA ali driver


--- linux/drivers/net/irda-d5/ali-ircc.c Thu Aug 29 12:13:51 2002
+++ linux/drivers/net/irda/ali-ircc.c Thu Aug 29 13:56:56 2002
@@ -251,6 +251,7 @@ static int ali_ircc_open(int i, chipio_t
struct ali_ircc_cb *self;
struct pm_dev *pmdev;
int dongle_id;
+ int ret;
int err;

IRDA_DEBUG(2, __FUNCTION__ "(), ---------------- Start ----------------\n");
@@ -530,6 +531,11 @@ static int ali_ircc_setup(chipio_t *info

IRDA_DEBUG(2, __FUNCTION__ "(), ---------------- Start ----------------\n");

+ /* Locking comments :
+ * Most operations here need to be protected. We are called before
+ * the device instance is created in ali_ircc_open(), therefore
+ * nobody can bother us - Jean II */
+
/* Switch to FIR space */
SIR2FIR(iobase);

@@ -937,6 +943,9 @@ static void ali_ircc_change_speed(struct

IRDA_DEBUG(2, __FUNCTION__ "(), setting speed = %d \n", baud);

+ /* This function *must* be called with irq off and spin-lock.
+ * - Jean II */
+
iobase = self->io.fir_base;

SetCOMInterrupts(self, FALSE); // 2000/11/24 11:43AM
@@ -1084,7 +1093,6 @@ static void ali_ircc_change_dongle_speed

struct ali_ircc_cb *self = (struct ali_ircc_cb *) priv;
int iobase,dongle_id;
- unsigned long flags;
int tmp = 0;

IRDA_DEBUG(1, __FUNCTION__ "(), ---------------- Start ----------------\n");
@@ -1092,8 +1100,7 @@ static void ali_ircc_change_dongle_speed
iobase = self->io.fir_base; /* or iobase = self->io.sir_base; */
dongle_id = self->io.dongle_id;

- save_flags(flags);
- cli();
+ /* We are already locked, no need to do it again */

IRDA_DEBUG(1, __FUNCTION__ "(), Set Speed for %s , Speed = %d\n", dongle_types[dongle_id], speed);

@@ -1259,8 +1266,6 @@ static void ali_ircc_change_dongle_speed

switch_bank(iobase, BANK0);

- restore_flags(flags);
-
IRDA_DEBUG(1, __FUNCTION__ "(), ----------------- End ------------------\n");
}

@@ -1440,20 +1445,26 @@ static int ali_ircc_fir_hard_xmit(struct

netif_stop_queue(dev);

+ /* Make sure tests *& speed change are atomic */
+ spin_lock_irqsave(&self->lock, flags);
+
+ /* Note : you should make sure that speed changes are not going
+ * to corrupt any outgoing frame. Look at nsc-ircc for the gory
+ * details - Jean II */
+
/* Check if we need to change the speed */
speed = irda_get_next_speed(skb);
if ((speed != self->io.speed) && (speed != -1)) {
/* Check for empty frame */
if (!skb->len) {
ali_ircc_change_speed(self, speed);
+ spin_unlock_irqrestore(&self->lock, flags);
dev_kfree_skb(skb);
return 0;
} else
self->new_speed = speed;
}

- spin_lock_irqsave(&self->lock, flags);
-
/* Register and copy this frame to DMA memory */
self->tx_fifo.queue[self->tx_fifo.free].start = self->tx_fifo.tail;
self->tx_fifo.queue[self->tx_fifo.free].len = skb->len;
@@ -1957,20 +1968,26 @@ static int ali_ircc_sir_hard_xmit(struct

netif_stop_queue(dev);

+ /* Make sure tests *& speed change are atomic */
+ spin_lock_irqsave(&self->lock, flags);
+
+ /* Note : you should make sure that speed changes are not going
+ * to corrupt any outgoing frame. Look at nsc-ircc for the gory
+ * details - Jean II */
+
/* Check if we need to change the speed */
speed = irda_get_next_speed(skb);
if ((speed != self->io.speed) && (speed != -1)) {
/* Check for empty frame */
if (!skb->len) {
ali_ircc_change_speed(self, speed);
+ spin_unlock_irqrestore(&self->lock, flags);
dev_kfree_skb(skb);
return 0;
} else
self->new_speed = speed;
}

- spin_lock_irqsave(&self->lock, flags);
-
/* Init tx buffer */
self->tx_buff.data = self->tx_buff.head;

@@ -2016,10 +2033,6 @@ static int ali_ircc_net_ioctl(struct net

IRDA_DEBUG(2, __FUNCTION__ "(), %s, (cmd=0x%X)\n", dev->name, cmd);

- /* Disable interrupts & save flags */
- save_flags(flags);
- cli();
-
switch (cmd) {
case SIOCSBANDWIDTH: /* Set bandwidth */
IRDA_DEBUG(1, __FUNCTION__ "(), SIOCSBANDWIDTH\n");
@@ -2031,7 +2044,9 @@ static int ali_ircc_net_ioctl(struct net
if (!in_interrupt() && !capable(CAP_NET_ADMIN))
return -EPERM;

+ spin_lock_irqsave(&self->lock, flags);
ali_ircc_change_speed(self, irq->ifr_baudrate);
+ spin_unlock_irqrestore(&self->lock, flags);
break;
case SIOCSMEDIABUSY: /* Set media busy */
IRDA_DEBUG(1, __FUNCTION__ "(), SIOCSMEDIABUSY\n");
@@ -2041,14 +2056,13 @@ static int ali_ircc_net_ioctl(struct net
break;
case SIOCGRECEIVING: /* Check if we are receiving right now */
IRDA_DEBUG(2, __FUNCTION__ "(), SIOCGRECEIVING\n");
+ /* This is protected */
irq->ifr_receiving = ali_ircc_is_receiving(self);
break;
default:
ret = -EOPNOTSUPP;
}

- restore_flags(flags);
-
IRDA_DEBUG(2, __FUNCTION__ "(), ----------------- End ------------------\n");

return ret;
@@ -2219,19 +2233,16 @@ static void SetCOMInterrupts(struct ali_
static void SIR2FIR(int iobase)
{
//unsigned char tmp;
- unsigned long flags;

IRDA_DEBUG(1, __FUNCTION__ "(), ---------------- Start ----------------\n");

- save_flags(flags);
- cli();
+ /* Already protected (change_speed() or setup()), no need to lock.
+ * Jean II */

outb(0x28, iobase+UART_MCR);
outb(0x68, iobase+UART_MCR);
outb(0x88, iobase+UART_MCR);

- restore_flags(flags);
-
outb(0x60, iobase+FIR_MCR); /* Master Reset */
outb(0x20, iobase+FIR_MCR); /* Master Interrupt Enable */

@@ -2245,12 +2256,11 @@ static void SIR2FIR(int iobase)
static void FIR2SIR(int iobase)
{
unsigned char val;
- unsigned long flags;

IRDA_DEBUG(1, __FUNCTION__ "(), ---------------- Start ----------------\n");

- save_flags(flags);
- cli();
+ /* Already protected (change_speed() or setup()), no need to lock.
+ * Jean II */

outb(0x20, iobase+FIR_MCR); /* IRQ to low */
outb(0x00, iobase+UART_IER);
@@ -2262,8 +2272,6 @@ static void FIR2SIR(int iobase)
val = inb(iobase+UART_RX);
val = inb(iobase+UART_LSR);
val = inb(iobase+UART_MSR);
-
- restore_flags(flags);

IRDA_DEBUG(1, __FUNCTION__ "(), ----------------- End ------------------\n");
}
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
\
 
 \ /
  Last update: 2005-03-22 13:28    [W:0.034 / U:0.204 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site