From: "Richard B. Johnson" <root@chaos.analogic.com>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Jeff Garzik <jgarzik@pobox.com>, Ross Biro <rossb@google.com>,
Alan Cox <alan@lxorguk.ukuu.org.uk>, Alan Cox <alan@redhat.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: Linux 2.4.21-pre3-ac4
Date: Mon, 13 Jan 2003 20:20:10 -0500 (EST) [thread overview]
Message-ID: <Pine.LNX.3.95.1030113201527.31662A-100000@chaos.analogic.com> (raw)
In-Reply-To: <1042495640.587.30.camel@zion.wanadoo.fr>
On 13 Jan 2003, Benjamin Herrenschmidt wrote:
> On Mon, 2003-01-13 at 22:40, Richard B. Johnson wrote:
>
> > There is a well-defined procedure for this. Any "read" anywhere
> > in the PCI address space, will force all posted writes to complete.
> > However, the "read" will not be the data one would obtain after
> > the write completes.
>
> Just to avoid confusion, the above is obviously wrong, the read will
> indeed force pending store queues to complete _in order_, the read will
> reach the device after the stores are complete and you'll read the value
> you would get after the write normally. At least on PCI ;)
>
> Ben.
>
It is not, as you say; "obviously wrong". It is, in fact correct.
If you think you will get, as previously stated, the current status
by reading the status register of a device, while a posted-write
is in-progress, the code is broken. There are warnings all over
PCI device hardware specifications about this.
Cheers,
Dick Johnson
Penguin : Linux version 2.4.18 on an i686 machine (797.90 BogoMips).
Why is the government concerned about the lunatic fringe? Think about it.
next prev parent reply other threads:[~2003-01-14 1:07 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-01-12 18:07 Linux 2.4.21-pre3-ac4 Alan Cox
2003-01-12 19:29 ` Benjamin Herrenschmidt
[not found] ` <1042403235.16288.14.camel@irongate.swansea.linux.org.uk>
2003-01-12 19:51 ` Benjamin Herrenschmidt
2003-01-12 19:57 ` Benjamin Herrenschmidt
2003-01-12 20:51 ` Alan Cox
2003-01-13 16:56 ` Benjamin Herrenschmidt
2003-01-12 20:40 ` Alan Cox
2003-01-12 20:02 ` Benjamin Herrenschmidt
2003-01-13 18:49 ` Ross Biro
2003-01-13 19:03 ` Benjamin Herrenschmidt
2003-01-13 19:19 ` Ross Biro
2003-01-13 19:32 ` Ross Biro
2003-01-13 21:05 ` Alan Cox
2003-01-13 20:36 ` Ross Biro
2003-01-13 19:46 ` Alan Cox
2003-01-14 17:38 ` Benjamin Herrenschmidt
2003-01-14 17:49 ` Ross Biro
2003-01-14 17:52 ` Benjamin Herrenschmidt
2003-01-14 21:17 ` Andre Hedrick
2003-01-15 0:23 ` Benjamin Herrenschmidt
2003-01-15 5:07 ` Andre Hedrick
[not found] ` <1043105473.12609.5.camel@dhcp22.swansea.linux.org.uk>
2003-01-21 17:07 ` Benjamin Herrenschmidt
2003-01-13 20:56 ` Benjamin Herrenschmidt
2003-01-13 21:36 ` Ross Biro
2003-01-14 1:35 ` Ross Biro
2003-01-14 1:44 ` Andre Hedrick
2003-01-14 9:18 ` Benjamin Herrenschmidt
2003-01-20 6:13 ` Alan Cox
2003-01-13 19:34 ` John Alvord
2003-01-13 19:48 ` Ross Biro
2003-01-13 21:24 ` Jeff Garzik
2003-01-13 21:40 ` Richard B. Johnson
2003-01-13 22:02 ` Benjamin Herrenschmidt
2003-01-13 22:07 ` Benjamin Herrenschmidt
2003-01-14 1:20 ` Richard B. Johnson [this message]
2003-01-14 9:06 ` Benjamin Herrenschmidt
2003-01-14 14:04 ` Richard B. Johnson
2003-01-14 14:35 ` Benjamin Herrenschmidt
2003-01-21 11:15 ` Linux 2.4.21-pre3-ac4 [PATCH] Paul Gortmaker
2003-01-21 13:21 ` Hugh Dickins
2003-01-21 11:46 ` small patch for Via Pro 266T agp-support Jurriaan
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=Pine.LNX.3.95.1030113201527.31662A-100000@chaos.analogic.com \
--to=root@chaos.analogic.com \
--cc=alan@lxorguk.ukuu.org.uk \
--cc=alan@redhat.com \
--cc=benh@kernel.crashing.org \
--cc=jgarzik@pobox.com \
--cc=linux-kernel@vger.kernel.org \
--cc=rossb@google.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
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;
as well as URLs for NNTP newsgroup(s).