Re: pci-express hotplug
From: Kenji Kaneshige
Date: Wed Oct 14 2009 - 01:28:31 EST
Jens Axboe wrote:
On Tue, Oct 13 2009, Kenji Kaneshige wrote:
Jens Axboe wrote:
On Tue, Oct 13 2009, Kenji Kaneshige wrote:
Jens Axboe wrote:
Hi,
I'm trying to get pci-express hotplug working in a box here. I don't
really care about the hotplug aspect, I just want the darn pci-e slots
that are designated hotplug slots to actually WORK. When I load pciehp,
I get:
Firmware did not grant requested _OSC control
Firmware did not grant requested _OSC control
Firmware did not grant requested _OSC control
Firmware did not grant requested _OSC control
pciehp 0000:00:05.0:pcie04: HPC vendor_id 8086 device_id 340c ss_vid 0 ss_did 0
pciehp 0000:00:05.0:pcie04: service driver pciehp loaded
Firmware did not grant requested _OSC control
pciehp 0000:00:07.0:pcie04: HPC vendor_id 8086 device_id 340e ss_vid 0 ss_did 0
pciehp 0000:00:07.0:pcie04: service driver pciehp loaded
Firmware did not grant requested _OSC control
pciehp 0000:80:07.0:pcie04: HPC vendor_id 8086 device_id 340e ss_vid 0 ss_did 0
pciehp 0000:80:07.0:pcie04: service driver pciehp loaded
pciehp 0000:80:09.0:pcie04: HPC vendor_id 8086 device_id 3410 ss_vid 0 ss_did 0
pciehp 0000:80:09.0:pcie04: service driver pciehp loaded
pciehp: PCI Express Hot Plug Controller Driver version: 0.4
and the devices in the hotplug slots stay off. Is this an ACPI/bios
issue? How can I debug this?
Could you give me the result of "ls -lR /sys/bus/pci/slots/"
after loading pciehp?
I have attached the result of that ls prior to loading pciehp/acpiphp
(pre-load), after loading pciehp (pciehp-load), and with acpiphp loaded
only as well (acpiphp-load).
Thank you for the info. From the information, I confirmed that hotplug
slots are detected by pciehp even though _OSC evaluation failed. There
are two ways to take control from the firmware through ACPI control
method. One is _OSC control method, and the other is OSHP control method.
I guess your ACPI fimware has both _OSC and OSHP on DSDT (ACPI Namespace),
and pciehp assumes that it took control through OSHP after the _OSC
evaluation failure. I think this pciehp's behavior is wrong because of
the following reasons and I think pciehp driver mis-detected the hotplug
slots on your environment because of this.
- According to the PCI firmware specification, pciehp driver must use the
result of _OSC, if the platform implements both _OSC and OSHP.
- OSHP control method seems only for SHPC, not for PCI Express native hot-
plug. So pciehp must not evaluate OSHP to take control from firmware.
To confirm this, could you send me the dmesg output after loading pciehp
with 'debug_acpi' of pci_hotplug (PCI hotplug core driver) enabled?
For example,
$ su
# echo Y > /sys/module/pci_hotplug/parameters/debug_acpi
# modprobe pciehp
# dmesg
See below.
And if it is possible, could you send me DSDT of your platform?
Not sure I can do that, I'll check.
Anyway, my recommendation is using acpiphp on your environment because
your firmware didn't grant control over hotplug control through _OSC.
From the information, acpiphp also detects the hotplug slots successfully.
Please try "echo 1 > /sys/bus/pci/slots/<slot#>/power". It would turn on
the slot and initialize adapter card on the slot.
It does find the 4 slots correctly. But if I try to turn on the power,
nothing happens and 'power' stays at 0. If I do the same with pciehp, I
get the same hang as described when using pciehp with pciehp_force=1.
But apparently this machine is getting a board replacement very soon, so
it may solve itself. Unless you think it should work and there's
something I can try to check, then lets just leave this issue until I
get it upgraded and return from kernel summit / JLS.
Could you try pciehp with "pciehp_debug" option enabled(*), and give me
the following information?
- "cat /sys/bus/pci/slots/*/*" output
- dmesg output after "echo 1 > /sys/bus/pci/slots/<slot#>/power"
(*) you can enable "pciehp_debug" option as follows
# modprobe pciehp pciehp_debug
I'm not sure, but I think one of the possibility is that your hot-plug
controller doesn't support power controller. On such slot, the slot is
usually turned on automatically at adapter card insertion. So card
re-insertion might make some difference.
By the way, I would like to know if your system has SHPC based hotplug
slots. Could you load shpchp driver and send me the
"ls -lR /sys/bus/pci/slots/" output? And I would like to see the dmesg
output with "debug_acpi" of pci_hotplug enabled. For example,
$ su
# echo Y > /sys/module/pci_hotplug/parameters/debug_acpi
# modprobe shpchp
# ls -lR /sys/bus/pci/slots
# dmesg
acpi_pcihp: acpi_get_hp_hw_control_from_firmware: Trying to get hotplug control for \_SB_.IOH0
Firmware did not grant requested _OSC control
acpi_pcihp: acpi_get_hp_hw_control_from_firmware: Trying to get hotplug control for \_SB_.IOH0.MRP5
acpi_pcihp: acpi_get_hp_hw_control_from_firmware: Gained control for hotplug HW for pci 0000:00:05.0 (\_SB_.IOH0.MRP5)
acpi_pcihp: acpi_get_hp_hw_control_from_firmware: Trying to get hotplug control for \_SB_.IOH0
Firmware did not grant requested _OSC control
acpi_pcihp: acpi_get_hp_hw_control_from_firmware: Trying to get hotplug control for \_SB_.IOH0.MRP7
acpi_pcihp: acpi_get_hp_hw_control_from_firmware: Gained control for hotplug HW for pci 0000:00:07.0 (\_SB_.IOH0.MRP7)
acpi_pcihp: acpi_get_hp_hw_control_from_firmware: Trying to get hotplug control for \_SB_.IOH0
Firmware did not grant requested _OSC control
acpi_pcihp: acpi_get_hp_hw_control_from_firmware: Trying to get hotplug control for \_SB_.IOH0.PEX0
acpi_pcihp: acpi_run_oshp: acpi_run_oshp:\_SB_.IOH0.PEX0 OSHP not found
acpi_pcihp: acpi_get_hp_hw_control_from_firmware: Trying to get hotplug control for \_SB_.IOH0
acpi_pcihp: acpi_run_oshp: acpi_run_oshp:\_SB_.IOH0 OSHP not found
acpi_pcihp: acpi_get_hp_hw_control_from_firmware: Cannot get control of hotplug hardware for pci 0000:00:1c.0
acpi_pcihp: acpi_get_hp_hw_control_from_firmware: Trying to get hotplug control for \_SB_.IOH1
acpi_pcihp: acpi_get_hp_hw_control_from_firmware: Trying to get hotplug control for \_SB_.IOH1.MRPI
acpi_pcihp: acpi_get_hp_hw_control_from_firmware: Gained control for hotplug HW for pci 0000:80:07.0 (\_SB_.IOH1.MRPI)
acpi_pcihp: acpi_get_hp_hw_control_from_firmware: Trying to get hotplug control for \_SB_.IOH1
acpi_pcihp: acpi_get_hp_hw_control_from_firmware: Trying to get hotplug control for \_SB_.IOH1.MRPK
acpi_pcihp: acpi_get_hp_hw_control_from_firmware: Gained control for hotplug HW for pci 0000:80:09.0 (\_SB_.IOH1.MRPK)
acpi_pcihp: acpi_get_hp_hw_control_from_firmware: Trying to get hotplug control for \_SB_.IOH0
Firmware did not grant requested _OSC control
acpi_pcihp: acpi_get_hp_hw_control_from_firmware: Trying to get hotplug control for \_SB_.IOH0.MRP5
acpi_pcihp: acpi_get_hp_hw_control_from_firmware: Gained control for hotplug HW for pci 0000:00:05.0 (\_SB_.IOH0.MRP5)
pciehp 0000:00:05.0:pcie04: HPC vendor_id 8086 device_id 340c ss_vid 0 ss_did 0
pciehp 0000:00:05.0:pcie04: service driver pciehp loaded
acpi_pcihp: acpi_get_hp_hw_control_from_firmware: Trying to get hotplug control for \_SB_.IOH0
Firmware did not grant requested _OSC control
acpi_pcihp: acpi_get_hp_hw_control_from_firmware: Trying to get hotplug control for \_SB_.IOH0.MRP7
acpi_pcihp: acpi_get_hp_hw_control_from_firmware: Gained control for hotplug HW for pci 0000:00:07.0 (\_SB_.IOH0.MRP7)
pciehp 0000:00:07.0:pcie04: HPC vendor_id 8086 device_id 340e ss_vid 0 ss_did 0
pciehp 0000:00:07.0:pcie04: service driver pciehp loaded
acpi_pcihp: acpi_get_hp_hw_control_from_firmware: Trying to get hotplug control for \_SB_.IOH0
Firmware did not grant requested _OSC control
acpi_pcihp: acpi_get_hp_hw_control_from_firmware: Trying to get hotplug control for \_SB_.IOH0.PEX0
acpi_pcihp: acpi_run_oshp: acpi_run_oshp:\_SB_.IOH0.PEX0 OSHP not found
acpi_pcihp: acpi_get_hp_hw_control_from_firmware: Trying to get hotplug control for \_SB_.IOH0
acpi_pcihp: acpi_run_oshp: acpi_run_oshp:\_SB_.IOH0 OSHP not found
acpi_pcihp: acpi_get_hp_hw_control_from_firmware: Cannot get control of hotplug hardware for pci 0000:00:1c.0
acpi_pcihp: acpi_get_hp_hw_control_from_firmware: Trying to get hotplug control for \_SB_.IOH1
acpi_pcihp: acpi_get_hp_hw_control_from_firmware: Trying to get hotplug control for \_SB_.IOH1.MRPI
acpi_pcihp: acpi_get_hp_hw_control_from_firmware: Gained control for hotplug HW for pci 0000:80:07.0 (\_SB_.IOH1.MRPI)
pciehp 0000:80:07.0:pcie04: HPC vendor_id 8086 _id 340e ss_vid 0 ss_did 0
pciehp 0000:80:07.0:pcie04: service driver pciehp loaded
acpi_pcihp: acpi_get_hp_hw_control_from_firmware: Trying to get hotplug control for \_SB_.IOH1
acpi_pcihp: acpi_get_hp_hw_control_from_firmware: Trying to get hotplug control for \_SB_.IOH1.MRPK
acpi_pcihp: acpi_get_hp_hw_control_from_firmware: Gained control for hotplug HW for pci 0000:80:09.0 (\_SB_.IOH1.MRPK)
pciehp 0000:80:09.0:pcie04: HPC vendor_id 8086 device_id 3410 ss_vid 0 ss_did 0
pciehp 0000:80:09.0:pcie04: service driver pciehp loaded
pciehp: PCI Express Hot Plug Controller Driver version: 0.4
It seems your environment has two PCI root bridges and one of them
(IOH0) provides both _OSC and OSHP, and the other (IOH1) provides
only OSHP. The _OSC under IOH0 doesn't grant hot-plug control, so
I think your system expects that at least the slots under IOH0 is
handled by acpiphp. But I don't have any idea about the slots
under IOH1 for now.
Thanks,
Kenji Kaneshige
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