From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Subject: Re: [net-next.git 2/7] stmmac: review barriers Date: Wed, 03 Apr 2013 18:02:08 +0400 Message-ID: <515C3660.7000909@cogentembedded.com> References: <1364967689-11155-1-git-send-email-peppe.cavallaro@st.com> <1364967689-11155-2-git-send-email-peppe.cavallaro@st.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, Deepak Sikri , Shiraz Hashim To: Giuseppe CAVALLARO Return-path: Received: from mail-lb0-f172.google.com ([209.85.217.172]:33229 "EHLO mail-lb0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1762599Ab3DCODH (ORCPT ); Wed, 3 Apr 2013 10:03:07 -0400 Received: by mail-lb0-f172.google.com with SMTP id u10so1627383lbi.31 for ; Wed, 03 Apr 2013 07:03:06 -0700 (PDT) In-Reply-To: <1364967689-11155-2-git-send-email-peppe.cavallaro@st.com> Sender: netdev-owner@vger.kernel.org List-ID: Hello. On 03-04-2013 9:41, Giuseppe CAVALLARO wrote: > In all my tests performed on SH4 and ARM A9 platforms, I've never met problems > that can be fixed by using memory barriers. In the past there was some issues > on SMP ARM but fixed by reviewing xmit spinlock. > Further barriers have been added in the commits too: 8e83989106562326bf Please also specify that commit's summary line in parens. > This patch is to use the smp_wbm instead of wbm because the driver It's "wmb". > runs on UP systems. Then, IMO it could make sense to only maintain the barriers > just in places where we touch the dma owner bits (that is the > only real critical path as we had seen and fixed in the commit: > eb0dc4bb2e22c04964d). This one's too. > Signed-off-by: Giuseppe Cavallaro > Cc: Deepak Sikri > Cc: Shiraz Hashim WBR, Sergei