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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.