[PATCH] forcedeth: hardirq lockdep warning

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>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 17 insertions, 14 deletions

diff --git a/drivers/net/forcedeth.c b/drivers/net/forcedeth.c
index eea1d66c530e..35467e0ac538 100644
--- a/drivers/net/forcedeth.c
+++ b/drivers/net/forcedeth.c
@@ -2497,6 +2497,7 @@ static irqreturn_t nv_nic_irq_tx(int foo, void *data, struct pt_regs *regs)
         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, void *data, struct pt_regs *regs)
                 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, void *data, struct pt_regs *regs)
                                 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, void *data, struct pt_regs *regs)
         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, void *data, struct pt_regs *regs)
 
                 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, void *data, struct pt_regs *regs)
                                 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 foo, void *data, struct pt_regs *regs)
         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 foo, void *data, struct pt_regs *regs)
                         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 foo, void *data, struct pt_regs *regs)
                                                 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 foo, void *data, struct pt_regs *regs)
                                 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;
                 }