From: Al Viro <viro@ZenIV.linux.org.uk>
To: dhananjay@netxen.com
Cc: netdev@vger.kernel.org, jeff@garzik.org
Subject: Re: [patch 7/7] netxen: fix byte-swapping in tx and rx
Date: Wed, 26 Dec 2007 22:38:03 +0000 [thread overview]
Message-ID: <20071226223803.GE27894@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20071226182928.425988922@netxen.com>
On Wed, Dec 26, 2007 at 10:23:59AM -0800, dhananjay@netxen.com wrote:
> This cleans up some unnecessary byte-swapping while setting up tx and
> interpreting rx desc. The 64 bit rx status data should be converted
> to host endian format only once and the macros just need to extract
> bitfields.
> - (cmd_desc)->flags_opcode |= cpu_to_le16((val) & 0x7f))
> + ((cmd_desc)->flags_opcode &= ~(0x7f), \
> + (cmd_desc)->flags_opcode |= (val) & 0x7f)
> #define netxen_set_cmd_desc_opcode(cmd_desc, val) \
> - ((cmd_desc)->flags_opcode &= ~cpu_to_le16(0x3f<<7), \
> - (cmd_desc)->flags_opcode |= cpu_to_le16(((val & 0x3f)<<7)))
> + ((cmd_desc)->flags_opcode &= ~(0x3f<<7), \
> + (cmd_desc)->flags_opcode |= ((val) & 0x3f) << 7)
_oh_?
That's actually a pessimisation and I'd rather see that conversion in
place gone - the thing will be less brittle that way.
BTW, note that cpu_to_le16() et.al. get evaluated by compiler when the
argument is constant.
next prev parent reply other threads:[~2007-12-26 22:38 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-12-26 18:23 [patch 0/7] netxen bug fixes dhananjay
2007-12-26 18:23 ` [patch 1/7] netxen: update MAINTAINERS dhananjay
2008-01-12 22:36 ` Jeff Garzik
2007-12-26 18:23 ` [patch 2/7] netxen: update driver version dhananjay
2007-12-26 18:23 ` [patch 3/7] netxen: improve MSI interrupt handling dhananjay
2008-01-12 22:37 ` Jeff Garzik
2007-12-26 18:23 ` [patch 4/7] netxen: stop second phy correctly dhananjay
2008-01-12 22:37 ` Jeff Garzik
2007-12-26 18:23 ` [patch 5/7] netxen: fix race in interrupt / napi dhananjay
2008-01-12 22:38 ` Jeff Garzik
2008-01-14 18:00 ` Dhananjay Phadke
2007-12-26 18:23 ` [patch 6/7] netxen: optimize tx handling dhananjay
2008-01-12 22:38 ` Jeff Garzik
2007-12-26 18:23 ` [patch 7/7] netxen: fix byte-swapping in tx and rx dhananjay
2007-12-26 22:38 ` Al Viro [this message]
2007-12-26 23:29 ` Dhananjay Phadke
2007-12-26 23:53 ` Al Viro
2007-12-31 18:08 ` Dhananjay Phadke
2008-01-12 22:38 ` Jeff Garzik
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=20071226223803.GE27894@ZenIV.linux.org.uk \
--to=viro@zeniv.linux.org.uk \
--cc=dhananjay@netxen.com \
--cc=jeff@garzik.org \
--cc=netdev@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;
as well as URLs for NNTP newsgroup(s).