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From: Yijing Wang <wangyijing@huawei.com>
To: "Wei, Aaron" <Aaron.Wei@emc.com>,
	"linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>
Subject: Re: A question about PCI device rescan
Date: Fri, 10 Oct 2014 09:38:37 +0800	[thread overview]
Message-ID: <5437389D.3050902@huawei.com> (raw)
In-Reply-To: <643A135C3423C4499CDC6CEE6EC6559D014710C96D@MX25A.corp.emc.com>

On 2014/10/9 18:50, Wei, Aaron wrote:
> Hi,
> 
> Could someone help explain why writing to "rescan" under "/sys/bus/pci/devices/.../rescan" will force a rescan of the device's parent bus instead of just re-discover all the devices behind this device (if the device is type-0, then nothing happens).
> 
> Is there any user space interface that could let user just rescan devices behind one specified type-1 device?

You can use pci_bus rescan which is placed under the pci_bus, i.e.

 \-[0000:00]-+-00.0  Intel Corporation 5520/5500/X58 I/O Hub to ESI Port
             +-01.0-[0000:01-02]--+-00.0  Intel Corporation 82576 Gigabit Network Connection
             |                    \-00.1  Intel Corporation 82576 Gigabit Network Connection

If you want to rescan devices behind 00:01.0(root port),
echo 1 > /sys/bus/pci/devices/0000:00:01.0/pci_bus/0000:01/rescan

Then it will only rescan the subordinate pci bus.


> 
> Thanks,
> Aaron 
> 
> --
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> 


-- 
Thanks!
Yijing


  reply	other threads:[~2014-10-10  1:38 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-10-09 10:50 A question about PCI device rescan Wei, Aaron
2014-10-10  1:38 ` Yijing Wang [this message]
2014-10-10  2:38   ` Wei, Aaron

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