From: "Timo Teräs" <timo.teras@iki•fi>
To: "François Romieu" <romieu@fr•zoreil.com>
Cc: Ivan Vecera <ivecera@redhat•com>, netdev@vger•kernel.org
Subject: Re: r8169 mac reading/writing broken
Date: Sat, 27 Mar 2010 22:37:38 +0200 [thread overview]
Message-ID: <4BAE6C92.2060801@iki.fi> (raw)
In-Reply-To: <4BADFAE4.5040906@iki.fi>
Timo Teräs wrote:
> François Romieu wrote:
>> Timo Teräs <timo.teras@iki•fi> :
>> [...]
>>> It seems that adding single printk between writing MAC0 and MAC4
>>> fixes it.
>>> I guess it needs a bit of delay between the writes or something.
>>
>> Can you test with a single RTL_R32 after each MACx write ?
>
> Adding reading back of the written value fixes it too. Though,
> disassembly says that it added an extra instructions also (needs to
> load the 'high' from stack before writing it) so the added delay is
> probably slightly more than just the io read.
I'm not too familiar with PCI details, but this smells a bit
like that write-combining is happening and the NIC does not like
that.
Any ideas how to check this?
The system experiencing this is a "VIA Eden 1.2Ghz" box.
Or is swapping MAC0/MAC4 writes, or adding the extra read an
acceptable fix/workaround?
- Timo
next prev parent reply other threads:[~2010-03-27 20:37 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 [this message]
2010-03-27 21:11 ` François Romieu
2010-03-27 23:20 ` Ben Hutchings
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=4BAE6C92.2060801@iki.fi \
--to=timo.teras@iki$(echo .)fi \
--cc=ivecera@redhat$(echo .)com \
--cc=netdev@vger$(echo .)kernel.org \
--cc=romieu@fr$(echo .)zoreil.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