RE: Q: state of pci express hotplug

From: Krishna Kothapalli
Date: Wed Feb 04 2009 - 13:17:32 EST




> Kenji Kaneshige wrote:
>
> Thank you for sending the information. I understood your
> hotplug slot can be handled by acpiphp or pciehp.
> More majordomo info at http://vger.kernel.org/majordomo-info.html

Tested this with 2.6.28.3 and details below:

>Could you give me the following additional information?
>o My understanding about the problem is:
> - Bad IRQ happen when you hot-add the device,

I don't see bad IRQ stack trace anymore, based on the steps you suggested. May be this is because I did not have hotplug driverloaded (and diff kernel build config) ?

> - and the device is not found in the lspci output

YES

> - and the device didn't show up under sysfs
> Am I correct?

YES

> o Details about the steps to reproduce the problem.

- boot the box with 2.6.28.3
- # /sbin/modprobe pciehp pciehp_debug
- lspci
- Insert the PCI express card on the hot swap slot and wait for 2 mins
- lspci <-- this does not show the PCI express device
(The same device shows up in lspci and sysfs during cold boot )

> o Does the problem happen with both acpiphp and pciehp?

That is correct.

> o The pciehp's debug output. We can get this as follows.
# /sbin/modprobe pciehp pciehp_debug
# dmesg | grep pciehp
pciehp 0000:00:09.0:pcie02: Hotplug Controller:
pciehp 0000:00:09.0:pcie02: Seg/Bus/Dev/Func/IRQ : 0000:00:09.0 IRQ 2295
pciehp 0000:00:09.0:pcie02: Vendor ID : 0x8086
pciehp 0000:00:09.0:pcie02: Device ID : 0x3410
pciehp 0000:00:09.0:pcie02: Subsystem ID : 0x0000
pciehp 0000:00:09.0:pcie02: Subsystem Vendor ID : 0x0000
pciehp 0000:00:09.0:pcie02: PCIe Cap offset : 0x90
pciehp 0000:00:09.0:pcie02: Slot Capabilities : 0x0302005f
pciehp 0000:00:09.0:pcie02: Physical Slot Number : 96
pciehp 0000:00:09.0:pcie02: Attention Button : yes
pciehp 0000:00:09.0:pcie02: Power Controller : yes
pciehp 0000:00:09.0:pcie02: MRL Sensor : yes
pciehp 0000:00:09.0:pcie02: Attention Indicator : yes
pciehp 0000:00:09.0:pcie02: Power Indicator : yes
pciehp 0000:00:09.0:pcie02: Hot-Plug Surprise : no
pciehp 0000:00:09.0:pcie02: EMI Present : yes
pciehp 0000:00:09.0:pcie02: Command Completed : yes
pciehp 0000:00:09.0:pcie02: Slot Status : 0x0020
pciehp 0000:00:09.0:pcie02: Slot Control : 0x078f
pciehp 0000:00:09.0:pcie02: Link Active Reporting supported
pciehp 0000:00:09.0:pcie02: Command not completed in 1000 msec
pciehp 0000:00:09.0:pcie02: HPC vendor_id 8086 device_id 3410 ss_vid 0 ss_did 0
pciehp 0000:00:09.0:pcie02: Command not completed in 1000 msec
pciehp 0000:00:09.0:pcie02: Registering domain:bus:dev=0000:09:00 hp_slot=0 sun=60 slot_device_offset=0
pciehp 0000:00:09.0:pcie02: get_power_status: physical_slot = 96
pciehp 0000:00:09.0:pcie02: hpc_get_power_status: SLOTCTRL a8 value read 7bf
pciehp 0000:00:09.0:pcie02: get_attention_status: physical_slot = 96
pciehp 0000:00:09.0:pcie02: hpc_get_attention_status: SLOTCTRL a8, value read 7bf
pciehp 0000:00:09.0:pcie02: get_latch_status: physical_slot = 96
pciehp 0000:00:09.0:pcie02: get_adapter_status: physical_slot = 96
pciehp 0000:00:09.0:pcie02: hpc_power_off_slot: slot->hp_slot 0
pciehp 0000:00:09.0:pcie02: Command not completed in 1000 msec
pciehp 0000:00:09.0:pcie02: hpc_power_off_slot: SLOTCTRL a8 write cmd 400
pciehp 0000:00:09.0:pcie02: service driver pciehp loaded
pciehp: pcie_port_service_register = 0
pciehp: PCI Express Hot Plug Controller Driver version: 0.4

-- Hot plug PCI express card and wait for 2 mins
-- no additional out put from dmesg

[root@localhost test]# /sbin/rmmod pciehp
[root@localhost test]# dmesg | grep pciehp
-- Additional output from dmesg after pciehp is unloaded ( but the express card is still present in the slot):-
pciehp: unload_pciehpd()
pciehp 0000:00:09.0:pcie02: unloading service driver pciehp
pciehp 0000:00:09.0:pcie02: release_slot: physical_slot = 96
pciehp 0000:00:09.0:pcie02: Command not completed in 1000 msec
pciehp 0000:00:09.0:pcie02: pcie_isr: intr_loc 8
pciehp 0000:00:09.0:pcie02: Presence/Notify input change
pciehp 0000:00:09.0:pcie02: Card present on Slot(øu'?)

-- removed the PCI express card from the slot

[root@localhost test]# ls -lt /sys/bus/pci/slots
total 0
[root@localhost test]# /sbin/modprobe acpiphp debug
[root@localhost test]# dmesg | grep acpiphp
acpiphp: ACPI Hot Plug PCI Controller Driver version: 0.5
acpiphp_glue: found PCI-to-PCI bridge at PCI 0000:00:09.0
acpiphp_glue: found ACPI PCI Hotplug slot 2 at PCI 0000:09:00
acpiphp: Slot [2] registered
acpiphp_glue: Bus 0000:09 has 1 slot
acpiphp_glue: Total 1 slots
[root@localhost test]#
[root@localhost test]# ls -lt /sys/bus/pci/slots
total 0
drwxr-xr-x 2 root root 0 2009-02-04 09:59 2
--- Insert PCI express card in the slot
[root@localhost test]# dmesg | grep acpiphp
[root@localhost test]# lspci | wc
105 1284 9203
[root@localhost test]# ls -lt /sys/bus/pci/slots/2/
total 0
-r--r--r-- 1 root root 4096 2009-02-04 10:01 adapter
-r--r--r-- 1 root root 4096 2009-02-04 10:01 address
-rw-r--r-- 1 root root 4096 2009-02-04 10:01 attention
-r--r--r-- 1 root root 4096 2009-02-04 10:01 latch
-rw-r--r-- 1 root root 4096 2009-02-04 10:01 power
[root@localhost test]#
[root@localhost test]# /sbin/rmmod acpiphp
[root@localhost test]# dmesg | grep acpiphp
acpiphp: Slot [2] unregistered
acpiphp: release_slot - physical_slot = 2
[root@localhost test]#



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