Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760641AbYBUJ0b (ORCPT ); Thu, 21 Feb 2008 04:26:31 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751840AbYBUJ0T (ORCPT ); Thu, 21 Feb 2008 04:26:19 -0500 Received: from mail.hevs.ch ([153.109.23.10]:38925 "EHLO mail.hevs.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752156AbYBUJ0R (ORCPT ); Thu, 21 Feb 2008 04:26:17 -0500 From: Marc Pignat Organization: HEVs To: Atsushi Nemoto Subject: Re: [PATCH] atmel_spi: support zero length transfer Date: Thu, 21 Feb 2008 10:26:16 +0100 User-Agent: KMail/1.9.7 Cc: hskinnemoen@atmel.com, david-b@pacbell.net, spi-devel-general@lists.sourceforge.net, linux-kernel@vger.kernel.org References: <20080221.005432.07645461.anemo@mba.ocn.ne.jp> <200802201855.02605.marc.pignat@hevs.ch> <20080221.105233.41199605.nemoto@toshiba-tops.co.jp> In-Reply-To: <20080221.105233.41199605.nemoto@toshiba-tops.co.jp> MIME-Version: 1.0 Content-Type: text/plain; charset="ansi_x3.4-1968" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200802211026.17816.marc.pignat@hevs.ch> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 707 Lines: 21 Hi! On Thursday 21 February 2008, Atsushi Nemoto wrote: ... > Yes. I tested it on AT91SAM9260 and it seems ENDRX rises soon. > Though it can be possible to avoid starting DMA for zero length > transfer, I think it is not worth to optimize for such a rare case. Ok, verified to work on at91rm9200, should be tested on AVR32. David, do you think writing 0 bytes is a valid use of this API? IMHO, we should add a fied to the spi_transfer struct. Regards Marc -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/