public inbox for linuxppc-dev@ozlabs.org 
 help / color / mirror / Atom feed
From: Michael Ellerman <michael@ellerman•id.au>
To: "Giffel, Brad" <Brad.Giffel@hbm•com>
Cc: linuxppc-dev@lists•ozlabs.org, Matthew Wilcox <matthew@wil•cx>
Subject: Re: Support for multiple MSI interrupts on MPC8377
Date: Thu, 03 Nov 2011 14:51:22 +1100	[thread overview]
Message-ID: <1320292282.3852.33.camel@concordia> (raw)
In-Reply-To: <FBC631D6B23BAB40AF19415483130F7A6FD458@HBMURBX.hbm.com>

[-- Attachment #1: Type: text/plain, Size: 929 bytes --]

On Wed, 2011-11-02 at 16:02 -0500, Giffel, Brad wrote:
> I’m working a project using a Spartan 6 FPGA with a PCIe interface and
> MSI interrupts.  I want to use multiple MSI interrupts (MSI-X is not
> supported in the FPGA PCIe core) but the current Linux distribution
> (3.0.8) prevents that (lines 23 to 25 in arch/powerpc/kernel/msi.c).
> 
>  
> 
> What’s the story here?  Is the code in place but not tested?  I tried
> commenting out those lines but a request_irq() called failed for the
> second interrupt requested.  Am I wasting my time here?  Should I
> re-architect to use a single MSI interrupt?

The short and easy answer is you should use a single MSI interrupt.

There is some code in place to support multiple MSI, but only in the
generic code (drivers/pci/msi.c), and I'm not sure if it's complete.
There is no arch support, for any arch AFAIK, and certainly not for
powerpc.

cheers



[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 198 bytes --]

  reply	other threads:[~2011-11-03  3:51 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-11-02 21:02 Support for multiple MSI interrupts on MPC8377 Giffel, Brad
2011-11-03  3:51 ` Michael Ellerman [this message]
2011-11-03 12:19   ` Giffel, Brad
2011-11-04 14:00   ` Matthew Wilcox

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1320292282.3852.33.camel@concordia \
    --to=michael@ellerman$(echo .)id.au \
    --cc=Brad.Giffel@hbm$(echo .)com \
    --cc=linuxppc-dev@lists$(echo .)ozlabs.org \
    --cc=matthew@wil$(echo .)cx \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox