[PATCH] forcedeth: hardirq lockdep warning

Peter Zijlstra
2006-09-19T12:53:28Z

BUG: warning at kernel/lockdep.c:1816/trace_hardirqs_on() (Not tainted)

Call Trace:
show_trace
dump_stack
trace_hardirqs_on
:forcedeth:nv_nic_irq_other
handle_IRQ_event
__do_IRQ
do_IRQ
ret_from_intr
DWARF2 barf
default_idle
cpu_idle
rest_init
start_kernel
_sinittext

These 3 functions nv_nic_irq_tx(), nv_nic_irq_rx() and nv_nic_irq_other()
are reachable from IRQ context and process context. Make use of the
irq-save/restore spinlock variant.

(Compile tested only, since I do not have the hardware)

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Andrew Morton <akpm@osdl.org>
---
drivers/net/forcedeth.c | 31 +++++++++++++++++--------------
1 file changed, 17 insertions(+), 14 deletions(-)

Index: linux-2.6-mm/drivers/net/forcedeth.c
===================================================================
--- linux-2.6-mm.orig/drivers/net/forcedeth.c
+++ linux-2.6-mm/drivers/net/forcedeth.c
@@ -2497,6 +2497,7 @@ static irqreturn_t nv_nic_irq_tx(int foo
u8 __iomem *base = get_hwbase(dev);
u32 events;
int i;
+ unsigned long flags;

dprintk(KERN_DEBUG "%s: nv_nic_irq_tx\n", dev->name);

@@ -2508,16 +2509,16 @@ static irqreturn_t nv_nic_irq_tx(int foo
if (!(events & np->irqmask))
break;

- spin_lock_irq(&np->lock);
+ spin_lock_irqsave(&np->lock, flags);
nv_tx_done(dev);
- spin_unlock_irq(&np->lock);
+ spin_unlock_irqrestore(&np->lock, flags);

if (events & (NVREG_IRQ_TX_ERR)) {
dprintk(KERN_DEBUG "%s: received irq with events 0x%x. Probably TX fail.\n",
dev->name, events);
}
if (i > max_interrupt_work) {
- spin_lock_irq(&np->lock);
+ spin_lock_irqsave(&np->lock, flags);
/* disable interrupts on the nic */
writel(NVREG_IRQ_TX_ALL, base + NvRegIrqMask);
pci_push(base);
@@ -2527,7 +2528,7 @@ static irqreturn_t nv_nic_irq_tx(int foo
mod_timer(&np->nic_poll, jiffies + POLL_WAIT);
}
printk(KERN_DEBUG "%s: too many iterations (%d) in nv_nic_irq_tx.\n", dev->name, i);
- spin_unlock_irq(&np->lock);
+ spin_unlock_irqrestore(&np->lock, flags);
break;
}

@@ -2601,6 +2602,7 @@ static irqreturn_t nv_nic_irq_rx(int foo
u8 __iomem *base = get_hwbase(dev);
u32 events;
int i;
+ unsigned long flags;

dprintk(KERN_DEBUG "%s: nv_nic_irq_rx\n", dev->name);

@@ -2614,14 +2616,14 @@ static irqreturn_t nv_nic_irq_rx(int foo

nv_rx_process(dev, dev->weight);
if (nv_alloc_rx(dev)) {
- spin_lock_irq(&np->lock);
+ spin_lock_irqsave(&np->lock, flags);
if (!np->in_shutdown)
mod_timer(&np->oom_kick, jiffies + OOM_REFILL);
- spin_unlock_irq(&np->lock);
+ spin_unlock_irqrestore(&np->lock, flags);
}

if (i > max_interrupt_work) {
- spin_lock_irq(&np->lock);
+ spin_lock_irqsave(&np->lock, flags);
/* disable interrupts on the nic */
writel(NVREG_IRQ_RX_ALL, base + NvRegIrqMask);
pci_push(base);
@@ -2631,7 +2633,7 @@ static irqreturn_t nv_nic_irq_rx(int foo
mod_timer(&np->nic_poll, jiffies + POLL_WAIT);
}
printk(KERN_DEBUG "%s: too many iterations (%d) in nv_nic_irq_rx.\n", dev->name, i);
- spin_unlock_irq(&np->lock);
+ spin_unlock_irqrestore(&np->lock, flags);
break;
}
}
@@ -2648,6 +2650,7 @@ static irqreturn_t nv_nic_irq_other(int
u8 __iomem *base = get_hwbase(dev);
u32 events;
int i;
+ unsigned long flags;

dprintk(KERN_DEBUG "%s: nv_nic_irq_other\n", dev->name);

@@ -2660,14 +2663,14 @@ static irqreturn_t nv_nic_irq_other(int
break;

if (events & NVREG_IRQ_LINK) {
- spin_lock_irq(&np->lock);
+ spin_lock_irqsave(&np->lock, flags);
nv_link_irq(dev);
- spin_unlock_irq(&np->lock);
+ spin_unlock_irqrestore(&np->lock, flags);
}
if (np->need_linktimer && time_after(jiffies, np->link_timeout)) {
- spin_lock_irq(&np->lock);
+ spin_lock_irqsave(&np->lock, flags);
nv_linkchange(dev);
- spin_unlock_irq(&np->lock);
+ spin_unlock_irqrestore(&np->lock, flags);
np->link_timeout = jiffies + LINK_TIMEOUT;
}
if (events & (NVREG_IRQ_UNKNOWN)) {
@@ -2675,7 +2678,7 @@ static irqreturn_t nv_nic_irq_other(int
dev->name, events);
}
if (i > max_interrupt_work) {
- spin_lock_irq(&np->lock);
+ spin_lock_irqsave(&np->lock, flags);
/* disable interrupts on the nic */
writel(NVREG_IRQ_OTHER, base + NvRegIrqMask);
pci_push(base);
@@ -2685,7 +2688,7 @@ static irqreturn_t nv_nic_irq_other(int
mod_timer(&np->nic_poll, jiffies + POLL_WAIT);
}
printk(KERN_DEBUG "%s: too many iterations (%d) in nv_nic_irq_other.\n", dev->name, i);
- spin_unlock_irq(&np->lock);
+ spin_unlock_irqrestore(&np->lock, flags);
break;
}