From: "Roland Vossen" <rvossen@broadcom.com>
To: "Johannes Berg" <johannes@sipsolutions.net>
Cc: "Michael Büsch" <m@bues.ch>, "gregkh@suse.de" <gregkh@suse.de>,
"devel@linuxdriverproject.org" <devel@linuxdriverproject.org>,
"linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>,
"linville@tuxdriver.com" <linville@tuxdriver.com>
Subject: Re: [PATCH 1/2] staging: brcm80211: removed #ifdef __mips__
Date: Wed, 20 Apr 2011 09:40:48 +0200 [thread overview]
Message-ID: <4DAE8E00.8040603@broadcom.com> (raw)
In-Reply-To: <1303221437.3603.7.camel@jlt3.sipsolutions.net>
On 04/19/2011 03:57 PM, Johannes Berg wrote:
> I don't see how write flushing would be MIPS specific anyway? It's a
> function of the bus (PCI), not the host architecture, no?
Since I am not the original author of that piece of code, I had to make
some inquiries, hence my non immediate response.
It turns out that the read-after-write construct was introduced in the
code to ensure write order for certain Broadcom chips. Those chips are:
bcm4706, bcm4716, bcm4717, bcm4718. All these chips contain a MIPS
processor.
The #ifdef __mips__ in the code is broader than just those chips. The
side effect is that other broadcom chips with a mips processor also
execute the extra read, leading to some I/O overhead, which is acceptable.
Bye, Roland.
next prev parent reply other threads:[~2011-04-20 7:41 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-19 7:13 [PATCH 0/2] staging: brcm80211: removal of obsolete mips code Roland Vossen
2011-04-19 7:13 ` [PATCH 1/2] staging: brcm80211: removed #ifdef __mips__ Roland Vossen
2011-04-19 12:10 ` Michael Büsch
2011-04-19 13:45 ` Roland Vossen
2011-04-19 13:49 ` Michael Büsch
2011-04-19 13:57 ` Johannes Berg
2011-04-20 7:40 ` Roland Vossen [this message]
2011-04-19 7:13 ` [PATCH 2/2] staging: brcm80211: removed BCMFASTPATH macro Roland Vossen
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=4DAE8E00.8040603@broadcom.com \
--to=rvossen@broadcom.com \
--cc=devel@linuxdriverproject.org \
--cc=gregkh@suse.de \
--cc=johannes@sipsolutions.net \
--cc=linux-wireless@vger.kernel.org \
--cc=linville@tuxdriver.com \
--cc=m@bues.ch \
/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).