From: "H. Peter Anvin" <hpa@zytor.com>
To: "Nakajima, Jun" <jun.nakajima@intel.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: PCI code: why need outb (0x01, 0xCFB); ?
Date: Wed, 08 Jan 2003 12:40:50 -0800 [thread overview]
Message-ID: <3E1C8CD2.4070402@zytor.com> (raw)
In-Reply-To: 3014AAAC8E0930438FD38EBF6DCEB5647D0D1C@fmsmsx407.fm.intel.com
Nakajima, Jun wrote:
>
> Normally all accesses should be long (0xcf8/0xcfc) but x86 is byte addresseable and some chipsets do support byte accesses.
> We do not encourage use of byte accesses as it will not be supported in future platforms.
>
The PCI standard is quite explicit: byte accesses are permitted to the
data window (0xCFC) and not permitted to the address window (0xCF8).
Accepting byte accesses to the address window, or not supporting byte
accesses to the data window, *will* result in breakage (I can attest to
this fact quite well.)
-hpa
next prev parent reply other threads:[~2003-01-08 20:32 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-01-08 19:10 PCI code: why need outb (0x01, 0xCFB); ? Nakajima, Jun
2003-01-08 20:40 ` H. Peter Anvin [this message]
2003-01-08 21:37 ` Richard B. Johnson
-- strict thread matches above, loose matches on Subject: below --
2003-01-08 21:33 Petr Vandrovec
2003-01-08 21:53 ` Maciej W. Rozycki
2003-01-08 20:49 Petr Vandrovec
2003-01-08 21:22 ` Maciej W. Rozycki
2003-01-07 2:24 fretre lewis
2003-01-06 13:02 fretre lewis
2003-01-06 9:26 fretre lewis
2003-01-06 12:41 ` Gianni Tedesco
2003-01-08 18:52 ` H. Peter Anvin
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=3E1C8CD2.4070402@zytor.com \
--to=hpa@zytor.com \
--cc=jun.nakajima@intel.com \
--cc=linux-kernel@vger.kernel.org \
/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