[PATCH] Fix crash in tg3 when using irqpoll

[PATCH] Fix crash in tg3 when using irqpoll

[Bernhard Walle]

When using irqpoll I had a crash when I loaded the tg3 network driver
(on IA64). The stack trace was:

        ia64_leave_kernel
        [tg3]tg3_interrupt_tagged
        note_interrupt
        __do_IRQ
        ia64_handle_irq
        ia64_leave_kernel
        _spin_unlock_irqrestore
        pci_bus_read_config_dword
        pci_restore_state
        [tg3]tg3_chip_reset
        [tg3]tg3_reset_hw
        [tg3]tg3_init_hw
        [tg3]tg3_open
        dev_open
        dev_change_flags
        devinet_ioctl
        inet_ioctl
        sock_ioctl
        do_ioctl
        vfs_ioctl
        sys_ioctl
        ia64_ret_from_syscall
        __kernel_syscall_via_break

Also, I had a MCA that ended up in a read from a PCI address that belongs to the
tg3 driver.

This patch makes sure that even the tr32() instruction in the interrupt handler
is not executed which accesses PCI memory. Accessing PCI memory when
pci_restore_state() is called is a bad idea because that function modifies
the BARs of the PCI device.

I think the problem could also happen when using shared interrupts, not only
irqpoll.


Signed-off-by: Bernhard Walle <bwalle@suse.de>

---
 drivers/net/tg3.c |   22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

Index: mainline-msi-init/drivers/net/tg3.c
===================================================================
--- mainline-msi-init.orig/drivers/net/tg3.c
+++ mainline-msi-init/drivers/net/tg3.c
@@ -3561,7 +3561,10 @@ static irqreturn_t tg3_interrupt(int irq
 	struct net_device *dev = dev_id;
 	struct tg3 *tp = netdev_priv(dev);
 	struct tg3_hw_status *sblk = tp->hw_status;
-	unsigned int handled = 1;
+	unsigned int handled = 0;
+
+	if (tg3_irq_sync(tp))
+		goto out;
 
 	/* In INTx mode, it is possible for the interrupt to arrive at
 	 * the CPU before the status block posted prior to the interrupt.
@@ -3579,8 +3582,6 @@ static irqreturn_t tg3_interrupt(int irq
 		 */
 		tw32_mailbox(MAILBOX_INTERRUPT_0 + TG3_64BIT_REG_LOW,
 			     0x00000001);
-		if (tg3_irq_sync(tp))
-			goto out;
 		sblk->status &= ~SD_STATUS_UPDATED;
 		if (likely(tg3_has_work(tp))) {
 			prefetch(&tp->rx_rcb[tp->rx_rcb_ptr]);
@@ -3592,8 +3593,7 @@ static irqreturn_t tg3_interrupt(int irq
 			tw32_mailbox_f(MAILBOX_INTERRUPT_0 + TG3_64BIT_REG_LOW,
 			     	0x00000000);
 		}
-	} else {	/* shared interrupt */
-		handled = 0;
+		handled = 1;
 	}
 out:
 	return IRQ_RETVAL(handled);
@@ -3604,7 +3604,10 @@ static irqreturn_t tg3_interrupt_tagged(
 	struct net_device *dev = dev_id;
 	struct tg3 *tp = netdev_priv(dev);
 	struct tg3_hw_status *sblk = tp->hw_status;
-	unsigned int handled = 1;
+	unsigned int handled = 0;
+
+	if (tg3_irq_sync(tp))
+		goto out;
 
 	/* In INTx mode, it is possible for the interrupt to arrive at
 	 * the CPU before the status block posted prior to the interrupt.
@@ -3622,8 +3625,6 @@ static irqreturn_t tg3_interrupt_tagged(
 		 */
 		tw32_mailbox(MAILBOX_INTERRUPT_0 + TG3_64BIT_REG_LOW,
 			     0x00000001);
-		if (tg3_irq_sync(tp))
-			goto out;
 		if (netif_rx_schedule_prep(dev)) {
 			prefetch(&tp->rx_rcb[tp->rx_rcb_ptr]);
 			/* Update last_tag to mark that this status has been
@@ -3634,8 +3635,7 @@ static irqreturn_t tg3_interrupt_tagged(
 			tp->last_tag = sblk->status_tag;
 			__netif_rx_schedule(dev);
 		}
-	} else {	/* shared interrupt */
-		handled = 0;
+		handled = 1;
 	}
 out:
 	return IRQ_RETVAL(handled);
@@ -7052,7 +7052,7 @@ static int tg3_open(struct net_device *d
 		return err;
 	}
 
-	tg3_full_lock(tp, 0);
+	tg3_full_lock(tp, 1);
 
 	err = tg3_init_hw(tp, 1);
 	if (err) {

Re: [PATCH] Fix crash in tg3 when using irqpoll

[Michael Chan]

On Thu, 2007-03-22 at 21:46 +0100, Bernhard Walle wrote:

> 
> This patch makes sure that even the tr32() instruction in the interrupt handler
> is not executed which accesses PCI memory. Accessing PCI memory when
> pci_restore_state() is called is a bad idea because that function modifies
> the BARs of the PCI device.

It is not caused by the BAR as it doesn't get changed in this case.  The
pci_restore_state() call is to restore the memory enable bit in the PCI
command register.  The tr32() call in tg3_interrupt() will cause a
master abort if it is called before the memory enable bit has been
restored.

> --- mainline-msi-init.orig/drivers/net/tg3.c
> +++ mainline-msi-init/drivers/net/tg3.c
> @@ -3561,7 +3561,10 @@ static irqreturn_t tg3_interrupt(int irq
>  	struct net_device *dev = dev_id;
>  	struct tg3 *tp = netdev_priv(dev);
>  	struct tg3_hw_status *sblk = tp->hw_status;
> -	unsigned int handled = 1;
> +	unsigned int handled = 0;
> +
> +	if (tg3_irq_sync(tp))
> +		goto out;


This will break other things.  When we disable interrupts, we set the
irq_sync flag but allow one more interrupt to be generated.  The irq
handler will simply mask off the interrupt when it sees the irq_sync
flag.  With the above change, the irq handler can no longer mask off
this trailing interrupt and you may get screaming interrupts as a
result.

Thanks for reporting this.  I'll try to come up with a good solution.

Re: [PATCH] Fix crash in tg3 when using irqpoll

[Bernhard Walle]

Hello Michael,

* Michael Chan <mchan@broadcom.com> [2007-03-22 23:04]:
> On Thu, 2007-03-22 at 21:46 +0100, Bernhard Walle wrote:
> 
> > This patch makes sure that even the tr32() instruction in the interrupt handler
> > is not executed which accesses PCI memory. Accessing PCI memory when
> > pci_restore_state() is called is a bad idea because that function modifies
> > the BARs of the PCI device.
> 
> It is not caused by the BAR as it doesn't get changed in this case.  The
> pci_restore_state() call is to restore the memory enable bit in the PCI
> command register.  The tr32() call in tg3_interrupt() will cause a
> master abort if it is called before the memory enable bit has been
> restored.

Ok, thanks for the explanation. I wondered why you call
pci_restore_state() here, normally that's only called from .resume
handlers.

> > --- mainline-msi-init.orig/drivers/net/tg3.c
> > +++ mainline-msi-init/drivers/net/tg3.c
> > @@ -3561,7 +3561,10 @@ static irqreturn_t tg3_interrupt(int irq
> >  	struct net_device *dev = dev_id;
> >  	struct tg3 *tp = netdev_priv(dev);
> >  	struct tg3_hw_status *sblk = tp->hw_status;
> > -	unsigned int handled = 1;
> > +	unsigned int handled = 0;
> > +
> > +	if (tg3_irq_sync(tp))
> > +		goto out;
> 
> 
> This will break other things.  When we disable interrupts, we set the
> irq_sync flag but allow one more interrupt to be generated.  The irq
> handler will simply mask off the interrupt when it sees the irq_sync
> flag.  With the above change, the irq handler can no longer mask off
> this trailing interrupt and you may get screaming interrupts as a
> result.

You're right, I had only the case in mind where the network device
doesn't generate any interrupts (in initialisation phase and in
shutdown phase) because it's disabled in the device, and the interrupt
handler is only called because of IRQ-sharing/irqpoll.

> Thanks for reporting this.  I'll try to come up with a good solution.

Could you please CC me, I'd like to test it here.


Thanks,
   Bernhard

[TG3 1/3]: Eliminate the unused TG3_FLAG_SPLIT_MODE flag.

[Michael Chan]

[TG3]: Eliminate the unused TG3_FLAG_SPLIT_MODE flag.

This flag to support multiple PCIX split completions was never used
because of hardware bugs.  This will make room for a new flag.

Signed-off-by: Michael Chan <mchan@broadcom.com>

diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index 8c8f9f4..ab87bb1 100644
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -6321,8 +6321,6 @@ static int tg3_reset_hw(struct tg3 *tp, int reset_phy)
 		      RDMAC_MODE_ADDROFLOW_ENAB | RDMAC_MODE_FIFOOFLOW_ENAB |
 		      RDMAC_MODE_FIFOURUN_ENAB | RDMAC_MODE_FIFOOREAD_ENAB |
 		      RDMAC_MODE_LNGREAD_ENAB);
-	if (tp->tg3_flags & TG3_FLAG_SPLIT_MODE)
-		rdmac_mode |= RDMAC_MODE_SPLIT_ENABLE;
 
 	/* If statement applies to 5705 and 5750 PCI devices only */
 	if ((GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5705 &&
@@ -6495,9 +6493,6 @@ static int tg3_reset_hw(struct tg3 *tp, int reset_phy)
 		} else if (GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5704) {
 			val &= ~(PCIX_CAPS_SPLIT_MASK | PCIX_CAPS_BURST_MASK);
 			val |= (PCIX_CAPS_MAX_BURST_CPIOB << PCIX_CAPS_BURST_SHIFT);
-			if (tp->tg3_flags & TG3_FLAG_SPLIT_MODE)
-				val |= (tp->split_mode_max_reqs <<
-					PCIX_CAPS_SPLIT_SHIFT);
 		}
 		tw32(TG3PCI_X_CAPS, val);
 	}
@@ -10863,14 +10858,6 @@ static int __devinit tg3_get_invariants(struct tg3 *tp)
 	grc_misc_cfg = tr32(GRC_MISC_CFG);
 	grc_misc_cfg &= GRC_MISC_CFG_BOARD_ID_MASK;
 
-	/* Broadcom's driver says that CIOBE multisplit has a bug */
-#if 0
-	if (GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5704 &&
-	    grc_misc_cfg == GRC_MISC_CFG_BOARD_ID_5704CIOBE) {
-		tp->tg3_flags |= TG3_FLAG_SPLIT_MODE;
-		tp->split_mode_max_reqs = SPLIT_MODE_5704_MAX_REQ;
-	}
-#endif
 	if (GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5705 &&
 	    (grc_misc_cfg == GRC_MISC_CFG_BOARD_ID_5788 ||
 	     grc_misc_cfg == GRC_MISC_CFG_BOARD_ID_5788M))
@@ -11968,14 +11955,12 @@ static int __devinit tg3_init_one(struct pci_dev *pdev,
 		       i == 5 ? '\n' : ':');
 
 	printk(KERN_INFO "%s: RXcsums[%d] LinkChgREG[%d] "
-	       "MIirq[%d] ASF[%d] Split[%d] WireSpeed[%d] "
-	       "TSOcap[%d] \n",
+	       "MIirq[%d] ASF[%d] WireSpeed[%d] TSOcap[%d]\n",
 	       dev->name,
 	       (tp->tg3_flags & TG3_FLAG_RX_CHECKSUMS) != 0,
 	       (tp->tg3_flags & TG3_FLAG_USE_LINKCHG_REG) != 0,
 	       (tp->tg3_flags & TG3_FLAG_USE_MI_INTERRUPT) != 0,
 	       (tp->tg3_flags & TG3_FLAG_ENABLE_ASF) != 0,
-	       (tp->tg3_flags & TG3_FLAG_SPLIT_MODE) != 0,
 	       (tp->tg3_flags2 & TG3_FLG2_NO_ETH_WIRE_SPEED) == 0,
 	       (tp->tg3_flags2 & TG3_FLG2_TSO_CAPABLE) != 0);
 	printk(KERN_INFO "%s: dma_rwctrl[%08x] dma_mask[%d-bit]\n",
diff --git a/drivers/net/tg3.h b/drivers/net/tg3.h
index 086892d..5df8f76 100644
--- a/drivers/net/tg3.h
+++ b/drivers/net/tg3.h
@@ -2223,7 +2223,6 @@ struct tg3 {
 #define TG3_FLAG_40BIT_DMA_BUG		0x08000000
 #define TG3_FLAG_BROKEN_CHECKSUMS	0x10000000
 #define TG3_FLAG_GOT_SERDES_FLOWCTL	0x20000000
-#define TG3_FLAG_SPLIT_MODE		0x40000000
 #define TG3_FLAG_INIT_COMPLETE		0x80000000
 	u32				tg3_flags2;
 #define TG3_FLG2_RESTART_TIMER		0x00000001
@@ -2262,9 +2261,6 @@ struct tg3 {
 #define TG3_FLG2_NO_FWARE_REPORTED	0x40000000
 #define TG3_FLG2_PHY_ADJUST_TRIM	0x80000000
 
-	u32				split_mode_max_reqs;
-#define SPLIT_MODE_5704_MAX_REQ		3
-
 	struct timer_list		timer;
 	u16				timer_counter;
 	u16				timer_multiplier;

[TG3 2/3]: Exit irq handler during chip reset.

[Michael Chan]

[TG3]: Exit irq handler during chip reset.

On most tg3 chips, the memory enable bit in the PCI command register
gets cleared during chip reset and must be restored before accessing
PCI registers using memory cycles.  The chip does not generate
interrupt during chip reset, but the irq handler can still be called
because of irq sharing or irqpoll.  Reading a register in the irq
handler can cause a master abort in this scenario and may result in a
crash on some architectures.

Use the TG3_FLAG_CHIP_RESETTING flag to tell the irq handler to exit
without touching any registers.  The checking of the flag is in the
"slow" path of the irq handler and will not affect normal performance.
The msi handler is not shared and therefore does not require checking
the flag.

Thanks to Bernhard Walle <bwalle@suse.de> for reporting the problem.

Signed-off-by: Michael Chan <mchan@broadcom.com>

diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index ab87bb1..9aca100 100644
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -3568,32 +3568,34 @@ static irqreturn_t tg3_interrupt(int irq, void *dev_id)
 	 * Reading the PCI State register will confirm whether the
 	 * interrupt is ours and will flush the status block.
 	 */
-	if ((sblk->status & SD_STATUS_UPDATED) ||
-	    !(tr32(TG3PCI_PCISTATE) & PCISTATE_INT_NOT_ACTIVE)) {
-		/*
-		 * Writing any value to intr-mbox-0 clears PCI INTA# and
-		 * chip-internal interrupt pending events.
-		 * Writing non-zero to intr-mbox-0 additional tells the
-		 * NIC to stop sending us irqs, engaging "in-intr-handler"
-		 * event coalescing.
-		 */
-		tw32_mailbox(MAILBOX_INTERRUPT_0 + TG3_64BIT_REG_LOW,
-			     0x00000001);
-		if (tg3_irq_sync(tp))
+	if (unlikely(!(sblk->status & SD_STATUS_UPDATED))) {
+		if ((tp->tg3_flags & TG3_FLAG_CHIP_RESETTING) ||
+		    (tr32(TG3PCI_PCISTATE) & PCISTATE_INT_NOT_ACTIVE)) {
+			handled = 0;
 			goto out;
-		sblk->status &= ~SD_STATUS_UPDATED;
-		if (likely(tg3_has_work(tp))) {
-			prefetch(&tp->rx_rcb[tp->rx_rcb_ptr]);
-			netif_rx_schedule(dev);		/* schedule NAPI poll */
-		} else {
-			/* No work, shared interrupt perhaps?  re-enable
-			 * interrupts, and flush that PCI write
-			 */
-			tw32_mailbox_f(MAILBOX_INTERRUPT_0 + TG3_64BIT_REG_LOW,
-			     	0x00000000);
 		}
-	} else {	/* shared interrupt */
-		handled = 0;
+	}
+
+	/*
+	 * Writing any value to intr-mbox-0 clears PCI INTA# and
+	 * chip-internal interrupt pending events.
+	 * Writing non-zero to intr-mbox-0 additional tells the
+	 * NIC to stop sending us irqs, engaging "in-intr-handler"
+	 * event coalescing.
+	 */
+	tw32_mailbox(MAILBOX_INTERRUPT_0 + TG3_64BIT_REG_LOW, 0x00000001);
+	if (tg3_irq_sync(tp))
+		goto out;
+	sblk->status &= ~SD_STATUS_UPDATED;
+	if (likely(tg3_has_work(tp))) {
+		prefetch(&tp->rx_rcb[tp->rx_rcb_ptr]);
+		netif_rx_schedule(dev);		/* schedule NAPI poll */
+	} else {
+		/* No work, shared interrupt perhaps?  re-enable
+		 * interrupts, and flush that PCI write
+		 */
+		tw32_mailbox_f(MAILBOX_INTERRUPT_0 + TG3_64BIT_REG_LOW,
+		     	0x00000000);
 	}
 out:
 	return IRQ_RETVAL(handled);
@@ -3611,31 +3613,33 @@ static irqreturn_t tg3_interrupt_tagged(int irq, void *dev_id)
 	 * Reading the PCI State register will confirm whether the
 	 * interrupt is ours and will flush the status block.
 	 */
-	if ((sblk->status_tag != tp->last_tag) ||
-	    !(tr32(TG3PCI_PCISTATE) & PCISTATE_INT_NOT_ACTIVE)) {
-		/*
-		 * writing any value to intr-mbox-0 clears PCI INTA# and
-		 * chip-internal interrupt pending events.
-		 * writing non-zero to intr-mbox-0 additional tells the
-		 * NIC to stop sending us irqs, engaging "in-intr-handler"
-		 * event coalescing.
-		 */
-		tw32_mailbox(MAILBOX_INTERRUPT_0 + TG3_64BIT_REG_LOW,
-			     0x00000001);
-		if (tg3_irq_sync(tp))
+	if (unlikely(sblk->status_tag == tp->last_tag)) {
+		if ((tp->tg3_flags & TG3_FLAG_CHIP_RESETTING) ||
+		    (tr32(TG3PCI_PCISTATE) & PCISTATE_INT_NOT_ACTIVE)) {
+			handled = 0;
 			goto out;
-		if (netif_rx_schedule_prep(dev)) {
-			prefetch(&tp->rx_rcb[tp->rx_rcb_ptr]);
-			/* Update last_tag to mark that this status has been
-			 * seen. Because interrupt may be shared, we may be
-			 * racing with tg3_poll(), so only update last_tag
-			 * if tg3_poll() is not scheduled.
-			 */
-			tp->last_tag = sblk->status_tag;
-			__netif_rx_schedule(dev);
 		}
-	} else {	/* shared interrupt */
-		handled = 0;
+	}
+
+	/*
+	 * writing any value to intr-mbox-0 clears PCI INTA# and
+	 * chip-internal interrupt pending events.
+	 * writing non-zero to intr-mbox-0 additional tells the
+	 * NIC to stop sending us irqs, engaging "in-intr-handler"
+	 * event coalescing.
+	 */
+	tw32_mailbox(MAILBOX_INTERRUPT_0 + TG3_64BIT_REG_LOW, 0x00000001);
+	if (tg3_irq_sync(tp))
+		goto out;
+	if (netif_rx_schedule_prep(dev)) {
+		prefetch(&tp->rx_rcb[tp->rx_rcb_ptr]);
+		/* Update last_tag to mark that this status has been
+		 * seen. Because interrupt may be shared, we may be
+		 * racing with tg3_poll(), so only update last_tag
+		 * if tg3_poll() is not scheduled.
+		 */
+		tp->last_tag = sblk->status_tag;
+		__netif_rx_schedule(dev);
 	}
 out:
 	return IRQ_RETVAL(handled);
@@ -4823,6 +4827,19 @@ static int tg3_chip_reset(struct tg3 *tp)
 	if (write_op == tg3_write_flush_reg32)
 		tp->write32 = tg3_write32;
 
+	/* Prevent the irq handler from reading or writing PCI registers
+	 * during chip reset when the memory enable bit in the PCI command
+	 * register may be cleared.  The chip does not generate interrupt
+	 * at this time, but the irq handler may still be called due to irq
+	 * sharing or irqpoll.
+	 */
+	tp->tg3_flags |= TG3_FLAG_CHIP_RESETTING;
+	tp->hw_status->status = 0;
+	tp->hw_status->status_tag = 0;
+	tp->last_tag = 0;
+	smp_mb();
+	synchronize_irq(tp->pdev->irq);
+
 	/* do the reset */
 	val = GRC_MISC_CFG_CORECLK_RESET;
 
@@ -4904,6 +4921,8 @@ static int tg3_chip_reset(struct tg3 *tp)
 
 	pci_restore_state(tp->pdev);
 
+	tp->tg3_flags &= ~TG3_FLAG_CHIP_RESETTING;
+
 	/* Make sure PCI-X relaxed ordering bit is clear. */
 	pci_read_config_dword(tp->pdev, TG3PCI_X_CAPS, &val);
 	val &= ~PCIX_CAPS_RELAXED_ORDERING;
diff --git a/drivers/net/tg3.h b/drivers/net/tg3.h
index 5df8f76..d515ed2 100644
--- a/drivers/net/tg3.h
+++ b/drivers/net/tg3.h
@@ -2223,6 +2223,7 @@ struct tg3 {
 #define TG3_FLAG_40BIT_DMA_BUG		0x08000000
 #define TG3_FLAG_BROKEN_CHECKSUMS	0x10000000
 #define TG3_FLAG_GOT_SERDES_FLOWCTL	0x20000000
+#define TG3_FLAG_CHIP_RESETTING		0x40000000
 #define TG3_FLAG_INIT_COMPLETE		0x80000000
 	u32				tg3_flags2;
 #define TG3_FLG2_RESTART_TIMER		0x00000001

[TG3 3/3]: Update version and reldate.

[Michael Chan]

[TG3]: Update version and reldate.

Update version to 3.75.

Signed-off-by: Michael Chan <mchan@broadcom.com>

diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index 9aca100..e682f90 100644
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -64,8 +64,8 @@
 
 #define DRV_MODULE_NAME		"tg3"
 #define PFX DRV_MODULE_NAME	": "
-#define DRV_MODULE_VERSION	"3.74"
-#define DRV_MODULE_RELDATE	"February 20, 2007"
+#define DRV_MODULE_VERSION	"3.75"
+#define DRV_MODULE_RELDATE	"March 23, 2007"
 
 #define TG3_DEF_MAC_MODE	0
 #define TG3_DEF_RX_MODE		0

Re: [TG3 1/3]: Eliminate the unused TG3_FLAG_SPLIT_MODE flag.

[David Miller]

From: "Michael Chan" <mchan@broadcom.com>
Date: Fri, 23 Mar 2007 16:12:57 -0800

> [TG3]: Eliminate the unused TG3_FLAG_SPLIT_MODE flag.
> 
> This flag to support multiple PCIX split completions was never used
> because of hardware bugs.  This will make room for a new flag.
> 
> Signed-off-by: Michael Chan <mchan@broadcom.com>

Applied.

Re: [TG3 2/3]: Exit irq handler during chip reset.

[David Miller]

From: "Michael Chan" <mchan@broadcom.com>
Date: Fri, 23 Mar 2007 16:13:07 -0800

> [TG3]: Exit irq handler during chip reset.
> 
> On most tg3 chips, the memory enable bit in the PCI command register
> gets cleared during chip reset and must be restored before accessing
> PCI registers using memory cycles.  The chip does not generate
> interrupt during chip reset, but the irq handler can still be called
> because of irq sharing or irqpoll.  Reading a register in the irq
> handler can cause a master abort in this scenario and may result in a
> crash on some architectures.
> 
> Use the TG3_FLAG_CHIP_RESETTING flag to tell the irq handler to exit
> without touching any registers.  The checking of the flag is in the
> "slow" path of the irq handler and will not affect normal performance.
> The msi handler is not shared and therefore does not require checking
> the flag.
> 
> Thanks to Bernhard Walle <bwalle@suse.de> for reporting the problem.
> 
> Signed-off-by: Michael Chan <mchan@broadcom.com>

Applied, except I fixed up some weird tabbing on this line:

> @@ -3568,32 +3568,34 @@ static irqreturn_t tg3_interrupt(int irq, void *dev_id)
 ...
> +	} else {
> +		/* No work, shared interrupt perhaps?  re-enable
> +		 * interrupts, and flush that PCI write
> +		 */
> +		tw32_mailbox_f(MAILBOX_INTERRUPT_0 + TG3_64BIT_REG_LOW,
> +		     	0x00000000);
                ^^^^^^^^

There are two tabs, some space characters, then a final tab,
and it doesn't even make the argument match up to the openning
parenthesis on the previous line :-)

Re: [TG3 3/3]: Update version and reldate.

[David Miller]

From: "Michael Chan" <mchan@broadcom.com>
Date: Fri, 23 Mar 2007 16:13:19 -0800

> [TG3]: Update version and reldate.
> 
> Update version to 3.75.
> 
> Signed-off-by: Michael Chan <mchan@broadcom.com>

Also applied, thanks a lot!