public inbox for netdev@vger.kernel.org 
 help / color / mirror / Atom feed
From: Grant Grundler <grundler@parisc-linux•org>
To: David Miller <davem@davemloft•net>
Cc: michael@ellerman•id.au, bhutchings@solarflare•com,
	somnath.kotur@emulex•com, netdev@vger•kernel.org,
	linux-pci@vger•kernel.org
Subject: Re: [PATCH net-next-2.6 1/2] be2net: Adding an option to use INTx instead of MSI-X
Date: Wed, 27 Oct 2010 23:37:14 -0600	[thread overview]
Message-ID: <20101028053714.GD32200@lackof.org> (raw)
In-Reply-To: <20101027.084604.226761472.davem@davemloft.net>

On Wed, Oct 27, 2010 at 08:46:04AM -0700, David Miller wrote:
> From: Michael Ellerman <michael@ellerman•id.au>
> Date: Wed, 27 Oct 2010 10:20:35 +1100
> 
> > On Tue, 2010-10-26 at 14:32 +0100, Ben Hutchings wrote:
> >> Michael Ellerman wrote:
> >> > On Mon, 2010-10-25 at 16:25 -0700, David Miller wrote:
> >> > > From: Ben Hutchings <bhutchings@solarflare•com>
> >> > > Date: Mon, 25 Oct 2010 23:38:53 +0100
> > 
> >> > Ethtool would be nice, but only for network drivers. Is there a generic
> >> > solution, quirks are obviously not keeping people happy.
> >>  
> >> Since this is (normally) a property of the system, pci=nomsi is the
> >> generic solution.
> > 
> > Sort of, it's a big hammer. Did all these driver writers not know about
> > pci=nomsi or did they prefer to add a parameter to their driver for some
> > reason?
> 
> Every time I've actually done the work to try and track down the
> true issue, it always turned out to be a PCI chipset problem rather
> than a device specific issue.

I agree with your generalization. I can think of only one exception:
ISTR pre-5705 tg3 chips would send both MSI and assert IRQ line at the same time.

My guess is driver writers just want knob to "work around" any issues
*their* driver might see with chipset. Disabling MSI for all drivers
doesn't leave opportunity for experimenting with individual drivers.

hth,
grant

> --
> To unsubscribe from this list: send the line "unsubscribe linux-pci" in
> the body of a message to majordomo@vger•kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

  reply	other threads:[~2010-10-28  5:37 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-10-25 11:12 [PATCH net-next-2.6 1/2] be2net: Adding an option to use INTx instead of MSI-X Somnath Kotur
2010-10-25 19:09 ` David Miller
2010-10-25 22:38   ` Ben Hutchings
2010-10-25 23:25     ` David Miller
2010-10-26  5:24       ` Somnath.Kotur
2010-10-26  6:52       ` Michael Ellerman
2010-10-26 13:32         ` Ben Hutchings
2010-10-26 23:20           ` Michael Ellerman
2010-10-27 15:46             ` David Miller
2010-10-28  5:37               ` Grant Grundler [this message]
2010-10-27 15:45         ` David Miller
2010-10-30 23:21         ` Matthew Wilcox
2010-11-03 12:45           ` Michael Ellerman
2010-11-03 15:28             ` David Miller

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=20101028053714.GD32200@lackof.org \
    --to=grundler@parisc-linux$(echo .)org \
    --cc=bhutchings@solarflare$(echo .)com \
    --cc=davem@davemloft$(echo .)net \
    --cc=linux-pci@vger$(echo .)kernel.org \
    --cc=michael@ellerman$(echo .)id.au \
    --cc=netdev@vger$(echo .)kernel.org \
    --cc=somnath.kotur@emulex$(echo .)com \
    /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