2005-04-28 20:44:44

by Mark Broadbent

Subject: [PATCH] Tulip interrupt uses non IRQ safe spinlock

The interrupt handling code in the tulip network driver appears to use a non
IRQ safe spinlock in an interrupt context. The following patch should correct
this.

Signed-off-by: Mark Broadbent <[email protected]>

Index: linux-2.6.11/drivers/net/tulip/interrupt.c
===================================================================
--- linux-2.6.11.orig/drivers/net/tulip/interrupt.c 2005-03-07 18:11:23.000000000 +0000
+++ linux-2.6.11/drivers/net/tulip/interrupt.c 2005-04-28 16:16:23.000000000 +0100
@@ -567,8 +567,9 @@

if (csr5 & (TxNoBuf | TxDied | TxIntr | TimerInt)) {
unsigned int dirty_tx;
+ unsigned long flags;

- spin_lock(&tp->lock);
+ spin_lock_irqsave(&tp->lock, flags);

for (dirty_tx = tp->dirty_tx; tp->cur_tx - dirty_tx > 0;
dirty_tx++) {
@@ -640,7 +641,7 @@
dev->name, csr5, ioread32(ioaddr + CSR6), tp->csr6);
tulip_restart_rxtx(tp);
}
- spin_unlock(&tp->lock);
+ spin_unlock_irqrestore(&tp->lock, flags);
}

/* Log errors. */

2005-05-02 14:16:20

by Paulo Marques

Subject: Re: [PATCH] Tulip interrupt uses non IRQ safe spinlock

Mark Broadbent wrote:
> The interrupt handling code in the tulip network driver appears to use a non
> IRQ safe spinlock in an interrupt context. The following patch should correct
> this.

Huh? Can a network interrupt handler be interrupted by the same interrupt?

AFAIK, the spin_lock_irqsave is to disable interruptions so that an
interrupt can not happen in the critical section, so that the interrupt
handler can not make modifications to shared data. Am I wrong?

--
Paulo Marques - http://www.grupopie.com

All that is necessary for the triumph of evil is that good men do nothing.
Edmund Burke (1729 - 1797)

2005-05-28 02:24:12

by Jeff Garzik

Subject: Re: [PATCH] Tulip interrupt uses non IRQ safe spinlock

Mark Broadbent wrote:
> The interrupt handling code in the tulip network driver appears to use a non
> IRQ safe spinlock in an interrupt context. The following patch should correct
> this.
>
> Signed-off-by: Mark Broadbent <[email protected]>
>
> Index: linux-2.6.11/drivers/net/tulip/interrupt.c
> ===================================================================
> --- linux-2.6.11.orig/drivers/net/tulip/interrupt.c 2005-03-07 18:11:23.000000000 +0000
> +++ linux-2.6.11/drivers/net/tulip/interrupt.c 2005-04-28 16:16:23.000000000 +0100
> @@ -567,8 +567,9 @@
>
> if (csr5 & (TxNoBuf | TxDied | TxIntr | TimerInt)) {
> unsigned int dirty_tx;
> + unsigned long flags;
>
> - spin_lock(&tp->lock);
> + spin_lock_irqsave(&tp->lock, flags);
>
> for (dirty_tx = tp->dirty_tx; tp->cur_tx - dirty_tx > 0;
> dirty_tx++) {
> @@ -640,7 +641,7 @@
> dev->name, csr5, ioread32(ioaddr + CSR6), tp->csr6);
> tulip_restart_rxtx(tp);
> }
> - spin_unlock(&tp->lock);
> + spin_unlock_irqrestore(&tp->lock, flags);

It's already inside the interrupt handler, so this patch is not needed.

Jeff