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From: Detlev Zundel <dzu@denx.de>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH] arm: Kirkwood: Add memory barriers to kwgbe_send/recv
Date: Fri, 03 Jul 2009 10:57:50 +0200	[thread overview]
Message-ID: <m2tz1unnxt.fsf@ohwell.denx.de> (raw)
In-Reply-To: <73173D32E9439E4ABB5151606C3E19E201EA4C04CD@SC-VEXCH1.marvell.com> (Prafulla Wadaskar's message of "Thu, 2 Jul 2009 01:12:08 -0700")

Hi Prafulla,

>> -----Original Message-----
>> From: Simon Kagstrom [mailto:simon.kagstrom at netinsight.net] 
>> Sent: Thursday, July 02, 2009 12:17 PM
>> To: Prafulla Wadaskar
>> Cc: U-Boot ML
>> Subject: Re: [U-Boot] [PATCH] arm: Kirkwood: Add memory 
>> barriers to kwgbe_send/recv
>> 
>> On Wed, 1 Jul 2009 09:57:10 -0700
>> Prafulla Wadaskar <prafulla@marvell.com> wrote:
>> > > kwgbe_send/recv both have loops waiting for the hardware 
>> to set  a 
>> > > bit.
>> > > GCC 4.3.3 cleverly optimizes this to ... a while(1); loop.
>> > Struct used is defined as volatile here.
>> > Is this not sufficient?
>> 
>> Right, but that was only for recv - send isn't volatile. I'll 
>> send a new patch with the required changes. The question is which :-):
>> 
>> 1. Make structure volatile in send as well
> Hi Simon
> I suggest to implement this change

Did you read Documentation/volatile-considered-harmful.txt in a Linux
source tree?

Cheers
  Detlev

-- 
Practice random senselessness and act kind of beautiful.
--
DENX Software Engineering GmbH,      MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich,  Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-40 Fax: (+49)-8142-66989-80 Email: dzu at denx.de

  reply	other threads:[~2009-07-03  8:57 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-07-01 15:16 [U-Boot] [PATCH] arm: Kirkwood: Add memory barriers to kwgbe_send/recv Simon Kagstrom
2009-07-01 16:56 ` Detlev Zundel
2009-07-01 17:09   ` Stefan Roese
2009-07-01 17:14     ` Scott Wood
2009-07-03  9:15       ` Detlev Zundel
2009-07-01 16:57 ` Prafulla Wadaskar
2009-07-02  6:47   ` Simon Kagstrom
2009-07-02  8:12     ` Prafulla Wadaskar
2009-07-03  8:57       ` Detlev Zundel [this message]
2009-07-04 23:52     ` Wolfgang Denk

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