From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1752598AbbKKTCz (ORCPT <rfc822;w@1wt.eu>);
	Wed, 11 Nov 2015 14:02:55 -0500
Received: from shards.monkeyblade.net ([149.20.54.216]:50125 "EHLO
	shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1751522AbbKKTCx convert rfc822-to-8bit (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Wed, 11 Nov 2015 14:02:53 -0500
Date: Wed, 11 Nov 2015 14:02:52 -0500 (EST)
Message-Id: <20151111.140252.2214540370641368590.davem@davemloft.net>
To: mans@mansr.com
Cc: romieu@fr.zoreil.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
        slash.tmp@free.fr
Subject: Re: [PATCH v5] net: ethernet: add driver for Aurora VLSI NB8800
 Ethernet controller
From: David Miller <davem@davemloft.net>
In-Reply-To: <yw1xk2poo0la.fsf@unicorn.mansr.com>
References: <yw1x6118pu0o.fsf@unicorn.mansr.com>
	<20151111.112423.1751428739163066569.davem@davemloft.net>
	<yw1xk2poo0la.fsf@unicorn.mansr.com>
X-Mailer: Mew version 6.6 on Emacs 24.5 / Mule 6.0 (HANACHIRUSATO)
Mime-Version: 1.0
Content-Type: Text/Plain; charset=iso-8859-1
Content-Transfer-Encoding: 8BIT
X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Wed, 11 Nov 2015 11:02:53 -0800 (PST)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

From: Måns Rullgård <mans@mansr.com>
Date: Wed, 11 Nov 2015 18:25:05 +0000

> If the TX DMA channel is idle when start_xmit is called, it can be
> started immediately.  Checking the DMA status and starting it if
> idle has to be done atomically somehow.

->ndo_start_xmit() is guaranteed to be invoked atomically, protected
by the TX queue spinlock.