From: Wolfgang Grandegger <wg@grandegger•com>
To: Oliver Hartkopp <socketcan@hartkopp•net>
Cc: Socketcan-core@lists•berlios.de,
Linux Netdev List <netdev@vger•kernel.org>
Subject: Re: [PATCH] Add Support for Freescale FlexCAN CAN controller
Date: Mon, 27 Jul 2009 12:07:58 +0200 [thread overview]
Message-ID: <4A6D7C7E.9050703@grandegger.com> (raw)
In-Reply-To: <4A6D76B7.8030105@hartkopp.net>
Oliver Hartkopp wrote:
> Wolfgang Grandegger wrote:
>> Sascha Hauer wrote:
>>> On Fri, Jul 24, 2009 at 04:55:02PM +0200, Wolfgang Grandegger wrote:
>
>
>> [...]
>>>>> + kfree_skb(skb);
>>>> Support for echo skb using can_put/get_echo_skb() is missing. It should
>>>> not be a big deal to add it.
>>> In fact it's not missing, but the hardware is configured to receive its
>>> own packets, so this isn't needed.
>> But the user may disable IFF_ECHO, which should be handled somehow.
>
> Really?
>
> IMO IFF_ECHO indicates the capability of the network driver to perform the MAC
> layer frame echo on driver level.
>
> Only when you have a CAN driver that does not have this capability (the 'bad'
> non default case) this flag is cleared.
>
> There is no need to provide a mode that can switch this functionality 'on' and
> 'off'. IFF_ECHO is just an indication provided by the driver.
>
> When the FlexCAN controller can 'receive' a sent frame, so that it reflects
> the correct message order on the bus, this is perfect.
>
> In this case Sascha should set the IFF_ECHO flag and he's done.
I thought the user can toggle the IFF_ECHO flag with the "ip" utility,
but obviously I'm wrong.
Wolfgang.
next prev parent reply other threads:[~2009-07-27 10:08 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-07-24 13:19 [PATCH] Add Support for Freescale FlexCAN CAN controller Sascha Hauer
2009-07-24 14:55 ` Wolfgang Grandegger
2009-07-27 6:25 ` Sascha Hauer
2009-07-27 8:30 ` Wolfgang Grandegger
2009-07-27 9:25 ` Wolfgang Grandegger
2009-07-27 9:43 ` Oliver Hartkopp
2009-07-27 10:07 ` Wolfgang Grandegger [this message]
2009-07-27 10:52 ` Oliver Hartkopp
2009-07-27 12:12 ` Wolfgang Grandegger
2009-07-28 7:40 ` Sascha Hauer
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