PCI HotPlug and Adding Resources after Linux Boots

[Morrison, Tom]

Thank you for taking the time in confirming some of the 
potential strategies I was already thinking about...:-)

I am going to try to pre-allocate some resources for
the specific port/slot/bridge device (because we know
at all times that port #6 (bus #5) is going to have
a FPGA end device associated with it...

Any other thoughts - whenever you can make them - would
be more than welcome!

Tom


>> -----Original Message-----
>> From: Benjamin Herrenschmidt [mailto:benh at kernel.crashing.org]
>> Sent: Wednesday, September 23, 2009 5:42 AM
>> To: Morrison, Tom
>> Cc: linuxppc-dev at ozlabs.org; linux-kernel at vger.kernel.org
>> Subject: Re: PCI HotPlug and Adding Resources after Linux Boots
>> 
>> On Tue, 2009-09-22 at 15:36 -0400, Morrison, Tom wrote:
>> > I am not exactly sure who to direct this question to (general Linux
>> > kernel or LinuxPPC),
>> 
>> PCI Hotplug is reasonably arch specific at the moment so I suppose
>> here's is as good as anywhere else to ask :-)
>> 
>> > so I am directing to both - in hopes that someone will recognize this
>> > problem - and perhaps
>> >
>> > give me some suggestions on how to proceed...
>> 
>> There's a few things you can do, though I don't have time just right now
>> to give you a detailed answer. I'll try again later.
>> 
>> In the meantime, some of the answers could be around not using full
>> automatic resource assignment, but instead, pre-initializing the top
>> bridge with some resources that are going to be enough for the device.
>> 
>> You can also try to get the bridge to re-allocate. There's various funky
>> locking issues with doing that though as long as it's during boot time,
>> it's not too much of a problem.
>> 
>> There are other more or less hackish ways to do it, but I'll have to
>> give it more thought.
>> 
>> I'm quite stretched at the moment so if you don't hear back from me in
>> the upcoming few days, don't hesitate to ping me again.
>> 
>> Cheers,
>> Ben.
>> >
>> > I am running Linux (2.6.23x (and 2.6.27.x)) on a MPC8572 based system.
>> 
[Morrison, Tom] 
<snip the rest original msg>