From: David Hawkins <dwh@ovro•caltech.edu>
To: Felix Radensky <felix@embedded-sol•com>
Cc: "linuxppc-dev@ozlabs•org list" <linuxppc-dev@ozlabs•org>,
Ira Snyder <iws@ovro•caltech.edu>
Subject: Re: MPC8536 PCI rescan to discover FPGA
Date: Mon, 21 Sep 2009 09:04:33 -0700 [thread overview]
Message-ID: <4AB7A411.3030406@ovro.caltech.edu> (raw)
In-Reply-To: <4AB79D41.60902@embedded-sol.com>
Hi Felix,
> On a custom MPC8536 board running linux-2.6.31,
> I'd like to load FPGA code from linux and then rescan
> PCI-E bus to discover FPGA device. Is that possible ?
> When linux boots FPGA is not loaded, so initial PCI
> scan does not detect it.
>
> I've tried playing with /sys/bus/pci/rescan and
> /sys/bus/pci/devices/.../rescan
> but didn't have much success.
This can be made to work using the kernel hot-swap
interface. PCI devices have an ENUM# interrupt that
they assert when inserted or extracted, and the host
hot-swap driver can be hooked up to it. PCI-E may
have a similar mechanism, if it does, then when your
FPGA configures as a PCI-E device, it can assert that
interrupt line (or send the appropriate PCI-E
message to simulate that interrupt).
However, even if PCI-E does not have the concept of
an ENUM# interrupt there is a way to generate a fake
hot-swap event and generate a re-scan of the PCI bus.
I haven't tested the kernel hot-swap interface, but I
know that Ira did, so I'll cc him on this mail, and he
can let you know what he tested.
Cheers,
Dave
next prev parent reply other threads:[~2009-09-21 17:05 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-09-21 15:35 MPC8536 PCI rescan to discover FPGA Felix Radensky
2009-09-21 16:04 ` David Hawkins [this message]
2009-09-22 7:23 ` Benjamin Herrenschmidt
2009-09-30 7:06 ` Felix Radensky
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