public inbox for netdev@vger.kernel.org 
 help / color / mirror / Atom feed
From: Ben Hutchings <ben@decadent•org.uk>
To: "François Romieu" <romieu@fr•zoreil.com>
Cc: "Timo Teräs" <timo.teras@iki•fi>,
	"Ivan Vecera" <ivecera@redhat•com>,
	netdev@vger•kernel.org
Subject: Re: r8169 mac reading/writing broken
Date: Sat, 27 Mar 2010 23:20:54 +0000	[thread overview]
Message-ID: <1269732054.8653.155.camel@localhost> (raw)
In-Reply-To: <20100327211133.GA3624@electric-eye.fr.zoreil.com>

[-- Attachment #1: Type: text/plain, Size: 1450 bytes --]

On Sat, 2010-03-27 at 22:11 +0100, François Romieu wrote:
> Timo Teräs <timo.teras@iki•fi> :
> [...]
> > Any ideas how to check this?
> 
> Check the datasheet of VIA's chipset for a WC control bit - there
> ought to be one - and disable it.
> 
> > Or is swapping MAC0/MAC4 writes, or adding the extra read an
> > acceptable fix/workaround?
> 
> swapping should reliably disable WC. It would be fine.

This bug was also reported by a Debian user in
<http://bugs.debian.org/573007>, also using a VIA chipset.

This sort of behaviour has been seen before with 64-bit registers
written in two 32-bit chunks, on some ARM platforms.  You worked around
that for the descriptor pointers with:

ommit b39fe41f481d20c201012e4483e76c203802dda7
Author: Francois Romieu <romieu@fr•zoreil.com>
Date:   Mon Sep 11 20:10:58 2006 +0200

    r8169: quirk for the 8110sb on arm platform

A similar problem seems to afflict the multicast hash register on this
platform - see <http://bugs.debian.org/407217>, and sorry I didn't
report this earlier when I got confirmation of my hypothesis.

I wonder whether there are special rules that need to be followed for
updating such registers and which the driver is not following, or a more
general bug in the Realtek chips that should be consistently
worked-around for all 64-bit registers.

Ben.

-- 
Ben Hutchings
Once a job is fouled up, anything done to improve it makes it worse.

[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 828 bytes --]

  reply	other threads:[~2010-03-27 23:21 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-03-27 10:28 r8169 mac reading/writing broken Timo Teräs
2010-03-27 11:40 ` François Romieu
2010-03-27 11:46   ` Timo Teräs
2010-03-27 12:03     ` François Romieu
2010-03-27 12:16       ` Timo Teräs
2010-03-27 12:25         ` Timo Teräs
2010-03-27 12:26         ` François Romieu
2010-03-27 12:32           ` Timo Teräs
2010-03-27 20:37             ` Timo Teräs
2010-03-27 21:11               ` François Romieu
2010-03-27 23:20                 ` Ben Hutchings [this message]
2010-03-27 23:30                   ` David Miller
2010-03-28  0:31                     ` [PATCH] r8169: fix broken register writes François Romieu
2010-03-28  0:47                       ` Ben Hutchings
2010-03-28 21:28                         ` François Romieu
2010-03-28 22:19                           ` Al Viro
2010-03-29  1:03                             ` Al Viro
2010-03-29  2:17                               ` Al Viro
2010-03-31 20:27                                 ` =?unknown-8bit?B?RnJhbsOnb2lz?= Romieu
2010-03-29 21:11                             ` François Romieu
2010-03-28  2:38                       ` David Miller
2010-03-28 22:04                         ` François Romieu

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=1269732054.8653.155.camel@localhost \
    --to=ben@decadent$(echo .)org.uk \
    --cc=ivecera@redhat$(echo .)com \
    --cc=netdev@vger$(echo .)kernel.org \
    --cc=romieu@fr$(echo .)zoreil.com \
    --cc=timo.teras@iki$(echo .)fi \
    /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