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From: Wolfgang Denk <wd@denx.de>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH 2/4] net: tweak eth_device layout to simplify enetaddr use
Date: Fri, 11 Nov 2011 12:55:45 +0100	[thread overview]
Message-ID: <20111111115545.8799C1404440@gemini.denx.de> (raw)
In-Reply-To: <1320970267-22297-2-git-send-email-vapier@gentoo.org>

Dear Mike Frysinger,

In message <1320970267-22297-2-git-send-email-vapier@gentoo.org> you wrote:
> The current eth_device leaves a 2 byte hole after "enetaddr" and before
> "iobase".  Since the enetaddr member has to be 6 bytes, we might as well
> fill that 2 byte hole with something useful.
> 
> Further, most device drivers want to load enetaddr from memory into the
> hardware as 1 32bit value and 1 16bit value.
> 
> So re-arrange the structure slightly, and add an anonymous union to make
> eth_device even better:
>  - expand the name field to fill the 2 byte hole
>  - make sure enetaddr is aligned, and provides 32bit/16bit members

I'm OK with expanding the name[] field, but as Thomas pointed out,
providing "convenient" u32 / u16 variables for the MAC address is
actually a faux ami that misleads people into using these variables
without thinking about endianess and such.

Please omit this part.

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
People seldom know what they want until you give them what  they  ask
for.

  parent reply	other threads:[~2011-11-11 11:55 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-11-11  0:11 [U-Boot] [PATCH 1/4] net/miiphy/serial: drop duplicate "NAMESIZE" define Mike Frysinger
2011-11-11  0:11 ` [U-Boot] [PATCH 2/4] net: tweak eth_device layout to simplify enetaddr use Mike Frysinger
2011-11-11 11:19   ` thomas.langer at lantiq.com
2011-11-11 11:55   ` Wolfgang Denk [this message]
2011-11-11 15:03     ` Mike Frysinger
2011-11-11 15:44       ` Andy Fleming
2011-11-11 16:06         ` Mike Frysinger
2011-12-05 21:06       ` Wolfgang Denk
2011-11-11  0:11 ` [U-Boot] [PATCH 3/4] Blackfin: bfin_mac: use new eth_device enetaddr members Mike Frysinger
2011-11-11  0:11 ` [U-Boot] [PATCH 4/4] usb: net: smsc95xx: attempt to fix enetaddr loading Mike Frysinger
2011-11-11 22:07 ` [U-Boot] [PATCH 1/4] net/miiphy/serial: drop duplicate "NAMESIZE" define Andy Fleming
2011-11-11 22:47   ` Mike Frysinger
2012-03-18 19:11 ` Wolfgang Denk

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