From: Shlomo Pongratz <shlomopongratz@gmail.com>
To: "Kaneshige, Kenji" <kaneshige.kenji@jp.fujitsu.com>
Cc: Greg KH <greg@kroah.com>,
"linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
"linux-hotplug@vger.kernel.org" <linux-hotplug@vger.kernel.org>
Subject: Re: Cabled PCIE device hotplug/hot-removal
Date: Tue, 31 Jul 2012 14:59:53 +0000 [thread overview]
Message-ID: <CAHzK-V3zHde2Kb0-63JftHVbda0MKWsS5TFtTyi6MqKwBJL_Og@mail.gmail.com> (raw)
In-Reply-To: <4A338DB2991D2A44B9A44B8718AECF650A477A44@G01JPEXMBYT03>
On Tue, Jul 31, 2012 at 2:02 PM, Kaneshige, Kenji
<kaneshige.kenji@jp.fujitsu.com> wrote:
>> -----Original Message-----
>> From: linux-pci-owner@vger.kernel.org
>> [mailto:linux-pci-owner@vger.kernel.org] On Behalf Of Shlomo Pongratz
>> Sent: Sunday, July 29, 2012 9:36 PM
>> To: Greg KH
>> Cc: linux-pci@vger.kernel.org; linux-hotplug@vger.kernel.org
>> Subject: Re: Cabled PCIE device hotplug/hot-removal
>>
>> On Thu, Jul 26, 2012 at 8:09 PM, Greg KH <greg@kroah.com> wrote:
>> > On Thu, Jul 26, 2012 at 08:03:09PM +0300, Shlomo Pongratz wrote:
>> >> Hi,
>> >>
>> >> I have a PCIe device connected with cables to a host (kernel 3.5.0-rc7+).
>> >> What are the handler I need to add to a driver in order to catch cable
>> >> pull-out / push-in?
>> >
>> > You shouldn't need anything special, aren't you already getting probe
>> > and disconnect callbacks when the device is discovered and removed?
>>
>
> Note that if the controller doesn't support "surprise removal", pciehp does
> nothing (just print a message) when plugging/unplugging the device. You need
> to power on the slot by "echo 1 > /sys/bus/pci/slots/XXX/power" after plugging
> the device. By this, pciehp will power on the slot and driver's .prove
> callback will be called. And for removal, you need to
> "echo 0 > /sys/bus/pci/slots/XXX/power" before unplugging the device. By doing
> this, driver's .remove callback will be called and then pciehp will power
> down the slot.
>
> If the controller supports "surprise removal" driver's .probe/.remove callbacks
> are called automatically by the pciehp's event handler when plugging/unplugging
> event (presence change detect event) happens.
>
>
>> When the device is loaded the probe is called
>> When I "echo 1" to the remove sysfs entry the remove callback is called.
>> But when I power down the card no callback is called.
>
> You need to "echo 0 > /sys/bus/pci/slots/XXX/power" to remove the device
> if you are using pciehp.
>
>
>> >
>> >> The pcisig presentation
>> >>
>> "http://www.pcisig.com/developers/main/training_materials/get_document
>> ?doc_idôca40ec1721aa7fadd05e2903b0172c36656294"
>> >> talks about PERST# detection for cabled PCIe hotplug.
>> >>
>> >> Does the kernel detect it?
>> >>
>> >> None of the pci_driver or pci_error_handlers callbacks were called
>> >> when using powered down/up the device (electrically).
>
> How did you power down/up the device (electrically)?
>
>> >
>> > Do you have the pciehp driver loaded properly when this happens?
>>
>> My {dot}config includes it into the kernel, i.e.
>> CONFIG_HOTPLUG_PCI_PCIE=y
>>
>
> You can see what kind of hot-plug driver manages the slot by checking
> /sys/bus/pci/slots/XXX/module symbolic link. On my system which has some
> PCIe hot-plug slots, I can see the following
>
> $ ls /sys/bus/pci/slots/* -l
> /sys/bus/pci/slots/21:
> total 0
> -r--r--r--. 1 root root 4096 Aug 1 02:55 adapter
> -r--r--r--. 1 root root 4096 Aug 1 02:55 address
> -rw-r--r--. 1 root root 4096 Aug 1 02:55 attention
> -r--r--r--. 1 root root 4096 Aug 1 02:55 cur_bus_speed
> -r--r--r--. 1 root root 4096 Aug 1 02:55 latch
> -r--r--r--. 1 root root 4096 Aug 1 02:55 max_bus_speed
> lrwxrwxrwx. 1 root root 0 Aug 1 02:55 module -> ../../../../module/pciehp
> -rw-r--r--. 1 root root 4096 Aug 1 02:55 power
>
> /sys/bus/pci/slots/22:
> <snip.>
>
> And pciehp_debug option might help you. With this option, you can get the
> controller infomation like below.
>
> pciehp 0000:0d:00.0:pcie24: Hotplug Controller:
> pciehp 0000:0d:00.0:pcie24: Seg/Bus/Dev/Func/IRQ : 0000:0d:00.0 IRQ 51
> pciehp 0000:0d:00.0:pcie24: Vendor ID : 0x111d
> pciehp 0000:0d:00.0:pcie24: Device ID : 0x807f
> pciehp 0000:0d:00.0:pcie24: Subsystem ID : 0x159c
> pciehp 0000:0d:00.0:pcie24: Subsystem Vendor ID : 0x10cf
> pciehp 0000:0d:00.0:pcie24: PCIe Cap offset : 0x40
> pciehp 0000:0d:00.0:pcie24: PCI resource [14] : [mem 0x92a00000-0x92bfffff]
> pciehp 0000:0d:00.0:pcie24: PCI resource [15] : [mem 0x92000000-0x921fffff 64bit pref]
> pciehp 0000:0d:00.0:pcie24: Slot Capabilities : 0x00a8005e
> pciehp 0000:0d:00.0:pcie24: Physical Slot Number : 21
> pciehp 0000:0d:00.0:pcie24: Attention Button : no
> pciehp 0000:0d:00.0:pcie24: Power Controller : yes
> pciehp 0000:0d:00.0:pcie24: MRL Sensor : yes
> pciehp 0000:0d:00.0:pcie24: Attention Indicator : yes
> pciehp 0000:0d:00.0:pcie24: Power Indicator : yes
> pciehp 0000:0d:00.0:pcie24: Hot-Plug Surprise : no
> pciehp 0000:0d:00.0:pcie24: EMI Present : no
> pciehp 0000:0d:00.0:pcie24: Command Completed : yes
> pciehp 0000:0d:00.0:pcie24: Slot Status : 0x0000
> pciehp 0000:0d:00.0:pcie24: Slot Control : 0x07c0
> pciehp 0000:0d:00.0:pcie24: Link Active Reporting supported
>
> Regards,
> Kenji Kaneshige
>
O.K. so if using lspci -vvv is see that with the PCI-bridge the slot
capability is marked with minus in the support surprise mode I need to
get another system.
That is
Capabilities: [6c] Express (v2) Root Port (Slot+), MSI 00
.....
SltCap: AttnBtn- PwrCtrl- MRL- AttnInd- PwrInd- HotPlug- Surpise-
Slot # 0, PowerLimit 0.000000; Interlock- NoCompl-
prev parent reply other threads:[~2012-07-31 14:59 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-26 17:03 Cabled PCIE device hotplug/hot-removal Shlomo Pongratz
2012-07-26 17:09 ` Greg KH
2012-07-29 12:36 ` Shlomo Pongratz
2012-07-29 14:59 ` Greg KH
2012-07-31 11:02 ` Kaneshige, Kenji
2012-07-31 14:59 ` Shlomo Pongratz [this message]
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