netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Marc Kleine-Budde <mkl@pengutronix.de>
To: Geert Uytterhoeven <geert@linux-m68k.org>,
	Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Cc: "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	wg@grandegger.com, linux-can@vger.kernel.org,
	Linux-sh list <linux-sh@vger.kernel.org>,
	vksavl@gmail.com
Subject: Re: [PATCH v5] can: add Renesas R-Car CAN driver
Date: Mon, 20 Jan 2014 12:47:13 +0100	[thread overview]
Message-ID: <52DD0CC1.70205@pengutronix.de> (raw)
In-Reply-To: <CAMuHMdWZJUvcW9OzM39aB2m+VdKqmZ6EOGR_rZcAdV7Cmwx3kg@mail.gmail.com>

[-- Attachment #1: Type: text/plain, Size: 1277 bytes --]

On 01/20/2014 12:43 PM, Geert Uytterhoeven wrote:
> Hi Sergei,
> 
> On Thu, Dec 26, 2013 at 10:37 PM, Sergei Shtylyov
> <sergei.shtylyov@cogentembedded.com> wrote:
>> Changes in version 3:
> 
>> - added '__packed' to 'struct rcar_can_mbox_regs' and 'struct rcar_can_regs';
>> - removed unneeded type cast in the probe() method.
> 
>> +/* Mailbox registers structure */
>> +struct rcar_can_mbox_regs {
>> +       u32 id;         /* IDE and RTR bits, SID and EID */
>> +       u8 stub;        /* Not used */
>> +       u8 dlc;         /* Data Length Code - bits [0..3] */
>> +       u8 data[8];     /* Data Bytes */
>> +       u8 tsh;         /* Time Stamp Higher Byte */
>> +       u8 tsl;         /* Time Stamp Lower Byte */
>> +} __packed;
> 
> Sorry, I missed the earlier discussion, but why the _packed?
> One u32 and 12 bytes makes a nice multiple of 4.

Better safe than sorry, it's the layout of the registers in hardware,
don't let the compiler optimize here.

Marc

-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
Industrial Linux Solutions        | Phone: +49-231-2826-924     |
Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 242 bytes --]

  reply	other threads:[~2014-01-20 11:47 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-12-26 21:37 [PATCH v5] can: add Renesas R-Car CAN driver Sergei Shtylyov
2014-01-13 13:46 ` Sergei Shtylyov
2014-01-20  9:18 ` Marc Kleine-Budde
2014-01-25  1:34   ` Sergei Shtylyov
2014-02-13 12:12     ` Marc Kleine-Budde
2014-02-20 23:48       ` Sergei Shtylyov
2014-02-28  9:08         ` Marc Kleine-Budde
2014-02-28 11:16           ` Sergei Shtylyov
2014-02-28 11:37             ` Marc Kleine-Budde
2014-02-28 11:41               ` Geert Uytterhoeven
2014-02-28 11:47                 ` David Laight
2014-02-28 11:50                   ` Marc Kleine-Budde
2014-02-28 12:02                     ` David Laight
2014-02-28 11:49                 ` Marc Kleine-Budde
2014-02-28 12:05                   ` Sergei Shtylyov
2014-02-28 12:17                     ` David Laight
2014-02-28 12:34                       ` Sergei Shtylyov
2014-01-20 11:43 ` Geert Uytterhoeven
2014-01-20 11:47   ` Marc Kleine-Budde [this message]
2014-01-20 11:52     ` Geert Uytterhoeven
2014-01-20 11:58       ` Marc Kleine-Budde
2014-01-20 12:02         ` Ben Dooks
2014-01-20 12:05           ` Geert Uytterhoeven
2014-01-20 12:08             ` Marc Kleine-Budde
2014-01-20 12:05           ` Marc Kleine-Budde
2014-01-20 12:13           ` David Laight
2014-01-20 12:35             ` Marc Kleine-Budde
2014-01-20 19:16         ` David Miller
2014-01-20 22:12           ` Sergei Shtylyov
2014-01-20 21:17             ` Marc Kleine-Budde
2014-01-22 11:52               ` Ben Dooks
2014-01-22 11:54                 ` Geert Uytterhoeven
2014-01-22 11:58                 ` David Laight
2014-01-20 12:12   ` Sergei Shtylyov

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=52DD0CC1.70205@pengutronix.de \
    --to=mkl@pengutronix.de \
    --cc=geert@linux-m68k.org \
    --cc=linux-can@vger.kernel.org \
    --cc=linux-sh@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=sergei.shtylyov@cogentembedded.com \
    --cc=vksavl@gmail.com \
    --cc=wg@grandegger.com \
    /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).