[PATCH] net/tg3: Support shutdown on PCI device

[Gavin Shan <shangw@linux.vnet.ibm.com>]

Before we tries to load new kernel with "kexec", we cound't bring
the tg3 NICs down manually because dhcp daemon keeps them up. So
there're still lots of traffic (DMA operations) on the tg3 card
from the old kernel while running the new kernel. It leads to
unnecessary EEH errors on Power platform because the network traffic
(from old kernel) breaks what we have in the IOMMU, which is built
by the new kernel.

	ifconfig eth0 down
	kexec -l vmlinux -c "root=/dev/sda5 debug" && kexec -f -e

The patch adds the shutdown interface for the PCI device to make
things more robust. The PCI device can be put to silent state before
loading the new kernel and to avoid unnecessary EEH errors.

Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
---
 drivers/net/ethernet/broadcom/tg3.c |   12 ++++++++++++
 1 files changed, 12 insertions(+), 0 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c
index ddebc7a..dc6178b 100644
--- a/drivers/net/ethernet/broadcom/tg3.c
+++ b/drivers/net/ethernet/broadcom/tg3.c
@@ -17663,6 +17663,17 @@ static void tg3_remove_one(struct pci_dev *pdev)
 	}
 }
 
+static void tg3_shutdown_one(struct pci_dev *pdev)
+{
+	struct net_device *dev = pci_get_drvdata(pdev);
+
+	if (!dev)
+		return;
+
+	netif_device_detach(dev);
+	tg3_remove_one(pdev);
+}
+
 #ifdef CONFIG_PM_SLEEP
 static int tg3_suspend(struct device *device)
 {
@@ -17909,6 +17920,7 @@ static struct pci_driver tg3_driver = {
 	.id_table	= tg3_pci_tbl,
 	.probe		= tg3_init_one,
 	.remove		= tg3_remove_one,
+	.shutdown	= tg3_shutdown_one,
 	.err_handler	= &tg3_err_handler,
 	.driver.pm	= &tg3_pm_ops,
 };
-- 
1.7.5.4