From 0c75ba22541ccea88e89782373991109a7ec2a54 Mon Sep 17 00:00:00 2001 From: Anton Blanchard Date: Wed, 28 Apr 2010 21:46:06 +0000 Subject: [PATCH] e1000e: Fix oops caused by ASPM patch. Commit 6f461f6c7c961f0b1b73c0f27becf472a0ac606b ("e1000e: enable/disable ASPM L0s and L1 and ERT according to hardware errata") oopses on one of my ppc64 boxes with a NULL pointer (0x4a): Unable to handle kernel paging request for data at address 0x0000004a Faulting instruction address: 0xc0000000004d2f1c cpu 0xe: Vector: 300 (Data Access) at [c000000bec1833a0] pc: c0000000004d2f1c: .e1000e_disable_aspm+0xe0/0x150 lr: c0000000004d2f0c: .e1000e_disable_aspm+0xd0/0x150 dar: 4a [c000000bec1836d0] c00000000069b9d8 .e1000_probe+0x84/0xe8c [c000000bec1837b0] c000000000386d90 .local_pci_probe+0x4c/0x68 [c000000bec183840] c0000000003872ac .pci_device_probe+0xfc/0x148 [c000000bec183900] c000000000409e8c .driver_probe_device+0xe4/0x1d0 [c000000bec1839a0] c00000000040a024 .__driver_attach+0xac/0xf4 [c000000bec183a40] c000000000409124 .bus_for_each_dev+0x9c/0x10c [c000000bec183b00] c000000000409c1c .driver_attach+0x40/0x60 [c000000bec183b90] c0000000004085dc .bus_add_driver+0x150/0x328 [c000000bec183c40] c00000000040a58c .driver_register+0x100/0x1c4 [c000000bec183cf0] c00000000038764c .__pci_register_driver+0x78/0x128 Seems like pdev->bus->self == NULL. I haven't touched pci in a long time so I'm trying to remember what this means (no pcie bridge perhaps?) The patch below fixes the oops for me. Signed-off-by: Anton Blanchard Reviewed-by: Bruce Allan Signed-off-by: David S. Miller --- drivers/net/e1000e/netdev.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/net/e1000e/netdev.c b/drivers/net/e1000e/netdev.c index fb8fc7d1b50..dbf81788bb4 100644 --- a/drivers/net/e1000e/netdev.c +++ b/drivers/net/e1000e/netdev.c @@ -4633,6 +4633,9 @@ static void __e1000e_disable_aspm(struct pci_dev *pdev, u16 state) reg16 &= ~state; pci_write_config_word(pdev, pos + PCI_EXP_LNKCTL, reg16); + if (!pdev->bus->self) + return; + pos = pci_pcie_cap(pdev->bus->self); pci_read_config_word(pdev->bus->self, pos + PCI_EXP_LNKCTL, ®16); reg16 &= ~state; -- 2.39.3