Help enabling PCI endpoint on 460EX, host sees disabled

Help enabling PCI endpoint on 460EX, host sees disabled

[Ayman El-Khashab]

My system consists of a pair of 460EXs attached by way of both PCI-E and
PCI.  Ultimately my goal is to communicate between them via pci-e (is
there anything out there that does this already?).  For a small step, I
am trying to get the PCI to work.  I already have the PCI boot ability
of the 460EXs working so the "adapter" processor is booting from the
masters main memory.  Right now I am trying to just exchange data via
the regular PCI bus.  I've looked through the kernel code and see where
it is using the "dma-ranges" from the device tree to setup the PIM
registers.  So I am good there.  When I look at the PCI bus from the
host though, I see the following output from lspci.
=20
0001:00:02.0 Class 0680: Unknown device 10e8:a003
        Subsystem: Unknown device 1014:cafe
        Flags: bus master, 66MHz, medium devsel, latency 128, IRQ 22
        Memory at d80000000 (64-bit, prefetchable) [disabled]
[size=3D80000000]
        Capabilities: [c0] Message Signalled Interrupts: Mask- 64bit+
Queue=3D0/2 Enable-
        Capabilities: [d0] Power Management version 2
        Capabilities: [dc] PCI-X non-bridge device
        Capabilities: [48] Vital Product Data

I am assuming that the disabled is probably because the pci command
register on the adapter is not correct.  However I am not entirely sure.
And I assume that the disabled means I won't be able to write to it.  So
what do I need to do to get this enabled?

Thanks

Re: Help enabling PCI endpoint on 460EX, host sees disabled

[Ira Snyder]

On Wed, Dec 10, 2008 at 05:29:53PM -0600, Ayman El-Khashab wrote:
> My system consists of a pair of 460EXs attached by way of both PCI-E and
> PCI.  Ultimately my goal is to communicate between them via pci-e (is
> there anything out there that does this already?).

I can't help you with that exact board, but I've written an "ethernet
over PCI" driver for Linux and U-Boot. The Linux driver has been posted
here on linuxppc-dev and on the lkml. Search for "net: add PCINet
driver" and you'll find it.

It won't work on your board, but it should serve as a good example about
how to communicate over PCI.

You are the third user asking for something like this recently. :) Too
bad the mainline kernel developers seem to be mostly ignoring the
driver I wrote.

Definitely get PCI/PCI-E working and stable before you try to start
communicating between the devices, though.

Ira

RE: Help enabling PCI endpoint on 460EX, host sees disabled

[Ayman El-Khashab]

> -----Original Message-----
> From: Ira Snyder [mailto:iws@ovro.caltech.edu]
> Sent: Wednesday, December 10, 2008 6:18 PM
> To: Ayman El-Khashab
> Cc: linuxppc-dev@ozlabs.org
> Subject: Re: Help enabling PCI endpoint on 460EX, host sees disabled
>=20
>=20
> I can't help you with that exact board, but I've written an "ethernet
> over PCI" driver for Linux and U-Boot. The Linux driver has=20
> been posted
> here on linuxppc-dev and on the lkml. Search for "net: add PCINet
> driver" and you'll find it.

Hello Ira, I am familiar with it, I looked through all of your posts and
the comments from RFCs 1-4.  That is what I was modeling mine after when
I ran across the "disabled" problem.  One thing I did not understand was
the device tree entries you made -- though that is unrelated to my=20
problem.
=20
> Definitely get PCI/PCI-E working and stable before you try to start
> communicating between the devices, though.

Thats my goal, there are a couple of things I am not sure about so I'm
sure I'll post again.

Re: Help enabling PCI endpoint on 460EX, host sees disabled

[Benjamin Herrenschmidt]

On Wed, 2008-12-10 at 16:17 -0800, Ira Snyder wrote:
> On Wed, Dec 10, 2008 at 05:29:53PM -0600, Ayman El-Khashab wrote:
> > My system consists of a pair of 460EXs attached by way of both PCI-E and
> > PCI.  Ultimately my goal is to communicate between them via pci-e (is
> > there anything out there that does this already?).
> 
> I can't help you with that exact board, but I've written an "ethernet
> over PCI" driver for Linux and U-Boot. The Linux driver has been posted
> here on linuxppc-dev and on the lkml. Search for "net: add PCINet
> driver" and you'll find it.
> 
> It won't work on your board, but it should serve as a good example about
> how to communicate over PCI.
> 
> You are the third user asking for something like this recently. :) Too
> bad the mainline kernel developers seem to be mostly ignoring the
> driver I wrote.

Don't get too disappointed... a lot of us are busy and things fall
through the cracks.. it may just be that we had nothing bad to say about
it :-)

Seriously, if you feel you didn't get useful reviews or that nothing is
picking it up, just holler, and nag us. We all have pretty full plates
and things do slip or just forgotten :-)

Cheers,
Ben.

Re: Help enabling PCI endpoint on 460EX, host sees disabled

[Ira Snyder]

On Thu, Dec 11, 2008 at 10:04:28PM +1100, Benjamin Herrenschmidt wrote:
> On Wed, 2008-12-10 at 16:17 -0800, Ira Snyder wrote:
> > On Wed, Dec 10, 2008 at 05:29:53PM -0600, Ayman El-Khashab wrote:
> > > My system consists of a pair of 460EXs attached by way of both PCI-E and
> > > PCI.  Ultimately my goal is to communicate between them via pci-e (is
> > > there anything out there that does this already?).
> > 
> > I can't help you with that exact board, but I've written an "ethernet
> > over PCI" driver for Linux and U-Boot. The Linux driver has been posted
> > here on linuxppc-dev and on the lkml. Search for "net: add PCINet
> > driver" and you'll find it.
> > 
> > It won't work on your board, but it should serve as a good example about
> > how to communicate over PCI.
> > 
> > You are the third user asking for something like this recently. :) Too
> > bad the mainline kernel developers seem to be mostly ignoring the
> > driver I wrote.
> 
> Don't get too disappointed... a lot of us are busy and things fall
> through the cracks.. it may just be that we had nothing bad to say about
> it :-)
> 
> Seriously, if you feel you didn't get useful reviews or that nothing is
> picking it up, just holler, and nag us. We all have pretty full plates
> and things do slip or just forgotten :-)
> 

Thanks Ben.

I'm still working on various issues with the hardware. Soon I'll be able
to easily test several boards in the same system at the same time. Once
I've proven that works, I'll start nagging :)

Is there a better subject line I should use to get attention, or should
I just start CC'ing people?

Sorry if I sounded negative in my post. It's just a little discouraging
when you don't get lots of feedback. I REALLY appreciate all of the work
you and everyone else is doing.

Ira

Re: Help enabling PCI endpoint on 460EX, host sees disabled

[Benjamin Herrenschmidt]

> I'm still working on various issues with the hardware. Soon I'll be able
> to easily test several boards in the same system at the same time. Once
> I've proven that works, I'll start nagging :)
> 
> Is there a better subject line I should use to get attention, or should
> I just start CC'ing people?

Not really. CC relevant lists like linuxppc-dev and netdev. If nothing
happens after a while, maybe ping me and/or jeff garzik privately.

> Sorry if I sounded negative in my post. It's just a little discouraging
> when you don't get lots of feedback. I REALLY appreciate all of the work
> you and everyone else is doing.

Well, it's annoying and heh, I don't get much feedback either on some of
my stuff :-) But there's a limited amount of people who can do useful
reviews and those are generally already very busy so ...

Cheers,
Ben.