public inbox for netdev@vger.kernel.org 
 help / color / mirror / Atom feed
From: Jeff Garzik <jeff@garzik•org>
To: Michael Buesch <mb@bu3sch•de>
Cc: Roland Dreier <rdreier@cisco•com>,
	Andi Kleen <andi@firstfloor•org>,
	ggrundstrom@neteffect•com, ewg@lists•openfabrics.org,
	netdev@vger•kernel.org
Subject: Re: [PATCH 2/14] nes: device structures and defines
Date: Wed, 08 Aug 2007 15:40:39 -0400	[thread overview]
Message-ID: <46BA1C37.5070208@garzik.org> (raw)
In-Reply-To: <200708081934.26293.mb@bu3sch.de>

Michael Buesch wrote:
> On Wednesday 08 August 2007 18:59:08 Jeff Garzik wrote:
>> Michael Buesch wrote:
>>> writel doesn't guarantee flushing either.
>>> readl does.
>>
>> Not quite -- there are multiple kinds of flushing.  You're thinking 
>> about flushing across PCI bridges, which is correct, but you also have 
>> CPU write posting and CPU write ordering and such.
>>
>> Without taking all that into account, you might be tempted to think that 
>> __raw_readl() will perform all flushes necessary following a 
>> __raw_writel() -- but that would be incorrect.
> 
> So, kind of...
> Better use writel(swab32(...
> unless you like being shot into the foot.

Correct.

	Jeff




  reply	other threads:[~2007-08-08 19:40 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-08-08  0:45 [PATCH 2/14] nes: device structures and defines ggrundstrom
2007-08-08  1:13 ` Jeff Garzik
2007-08-08 12:38   ` Andi Kleen
2007-08-08 11:50     ` Michael Buesch
2007-08-08 12:55       ` Andi Kleen
2007-08-08 13:02         ` Michael Buesch
2007-08-08 13:08           ` Andi Kleen
2007-08-08 13:28             ` Michael Buesch
2007-08-08 13:38               ` Andi Kleen
2007-08-08 13:48                 ` Michael Buesch
2007-08-08 13:55                   ` Michael Buesch
2007-08-08 16:18                     ` Roland Dreier
2007-08-08 16:25                       ` Jeff Garzik
2007-08-08 16:30                       ` Michael Buesch
2007-08-08 16:33                         ` Jeff Garzik
2007-08-08 16:43                           ` Michael Buesch
2007-08-08 16:46                             ` Roland Dreier
2007-08-08 16:57                               ` akepner
2007-08-08 16:59                             ` Jeff Garzik
2007-08-08 17:34                               ` Michael Buesch
2007-08-08 19:40                                 ` Jeff Garzik [this message]
2007-08-08 16:39                         ` Roland Dreier
2007-08-08 16:19     ` Jeff Garzik
2007-08-08 22:04     ` 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=46BA1C37.5070208@garzik.org \
    --to=jeff@garzik$(echo .)org \
    --cc=andi@firstfloor$(echo .)org \
    --cc=ewg@lists$(echo .)openfabrics.org \
    --cc=ggrundstrom@neteffect$(echo .)com \
    --cc=mb@bu3sch$(echo .)de \
    --cc=netdev@vger$(echo .)kernel.org \
    --cc=rdreier@cisco$(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