Hello Kenji-san, I'm hitting a BUG_ON() in pcie_update_aspm_capable(), introduced in 07d92760d2ee542fe932f4e8b5807dd98481d1fd during a PCI logical hotplug operation. I don't understand the intent of the BUG_ON(root->parent). It doesn't seem like it's exactly necessary to me, but I admit that I don't understand the ASPM design very well. Thanks, /ac dl785a:/sys/bus/pci # lspci -vt -+-[0000:c0]-+-13.0-[0000:c1-c3]-- | +-14.0-[0000:c7]-- | +-15.0-[0000:c8]-- | +-16.0-[0000:c4-c6]-- | \-17.0-[0000:c9]-- +-[0000:80]-+-13.0-[0000:81-83]-- | +-14.0-[0000:87]-- | +-15.0-[0000:88]-- | +-16.0-[0000:84-86]-- | \-17.0-[0000:89]-- +-[0000:40]-+-13.0-[0000:41-43]--+-00.0 Intel Corporation 82571EB Gigabit Ethernet Controller | | \-00.1 Intel Corporation 82571EB Gigabit Ethernet Controller | +-14.0-[0000:4a]-- | +-15.0-[0000:4b]-- | +-16.0-[0000:44-46]-- | \-17.0-[0000:47-49]-- dl785a:/sys/bus/pci # echo 1 > devices/0000:40:13.0/remove ------------[ cut here ]------------ kernel BUG at drivers/pci/pcie/aspm.c:606! invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC last sysfs file: /sys/devices/pci0000:40/0000:40:13.0/remove CPU 1 Modules linked in: shpchp Pid: 9345, comm: sysfsd Not tainted 2.6.32-rc5 #98 ProLiant DL785 G6 RIP: 0010:[<ffffffff811df69b>] [<ffffffff811df69b>] pcie_update_aspm_capable+0x15/0xbe RSP: 0018:ffff88082a2f5ca0 EFLAGS: 00010202 RAX: 0000000000000e77 RBX: ffff88182cc3e000 RCX: ffff88082a33d006 RDX: 0000000000000001 RSI: ffffffff811dff4a RDI: ffff88182cc3e000 RBP: ffff88082a2f5cc0 R08: ffff88182cc3e000 R09: 0000000000000000 R10: ffff88182fc00180 R11: ffff88182fc00198 R12: ffff88182cc3e000 R13: 0000000000000000 R14: ffff88182cc3e000 R15: ffff88082a2f5e20 FS: 00007f259a64b6f0(0000) GS:ffff880864600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b CR2: 00007feb53f73da0 CR3: 000000102cc94000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process sysfsd (pid: 9345, threadinfo ffff88082a2f4000, task ffff88082a33cf00) Stack: ffff88182cc3e000 ffff88182cc3e000 0000000000000000 ffff88082a33cf00 <0> ffff88082a2f5cf0 ffffffff811dff52 ffff88082a2f5cf0 ffff88082c525168 <0> ffff88402c9fd2f8 ffff88402c9fd2f8 ffff88082a2f5d20 ffffffff811d7db2 Call Trace: [<ffffffff811dff52>] pcie_aspm_exit_link_state+0xf5/0x11e [<ffffffff811d7db2>] pci_stop_bus_device+0x76/0x7e [<ffffffff811d7d67>] pci_stop_bus_device+0x2b/0x7e [<ffffffff811d7e4f>] pci_remove_bus_device+0x15/0xb9 [<ffffffff811dcb8c>] remove_callback+0x29/0x3a [<ffffffff81135aeb>] sysfs_schedule_callback_work+0x15/0x6d [<ffffffff81072790>] worker_thread+0x19d/0x298 [<ffffffff8107273b>] ? worker_thread+0x148/0x298 [<ffffffff81135ad6>] ? sysfs_schedule_callback_work+0x0/0x6d [<ffffffff810765c0>] ? autoremove_wake_function+0x0/0x38 [<ffffffff810725f3>] ? worker_thread+0x0/0x298 [<ffffffff8107629e>] kthread+0x7d/0x85 [<ffffffff8102eafa>] child_rip+0xa/0x20 [<ffffffff8102e4bc>] ? restore_args+0x0/0x30 [<ffffffff81076221>] ? kthread+0x0/0x85 [<ffffffff8102eaf0>] ? child_rip+0x0/0x20 Code: 89 e5 8a 50 48 31 c0 c0 ea 03 83 e2 07 e8 b2 de fe ff c9 48 98 c3 55 48 89 e5 41 56 49 89 fe 41 55 41 54 53 48 83 7f 10 00 74 04 <0f> 0b eb fe 48 8b 05 da 7d 63 00 4c 8d 60 e8 4c 89 e1 eb 24 4c RIP [<ffffffff811df69b>] pcie_update_aspm_capable+0x15/0xbe RSP <ffff88082a2f5ca0> ---[ end trace 6ae0f65bdeab8555 ]--- -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html