Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752932AbZGXNuQ (ORCPT ); Fri, 24 Jul 2009 09:50:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752786AbZGXNuP (ORCPT ); Fri, 24 Jul 2009 09:50:15 -0400 Received: from mba.ocn.ne.jp ([122.28.14.163]:54689 "EHLO smtp.mba.ocn.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752779AbZGXNuO (ORCPT ); Fri, 24 Jul 2009 09:50:14 -0400 X-Greylist: delayed 1252 seconds by postgrey-1.27 at vger.kernel.org; Fri, 24 Jul 2009 09:50:14 EDT Date: Fri, 24 Jul 2009 22:29:19 +0900 (JST) Message-Id: <20090724.222919.240484146.anemo@mba.ocn.ne.jp> To: nicolas.ferre@atmel.com Cc: dan.j.williams@intel.com, maciej.sosnowski@intel.com, linux-arm-kernel@lists.arm.linux.org.uk, patrice.vilchez@atmel.com, linux-kernel@vger.kernel.org, haavard.skinnemoen@atmel.com Subject: Re: [PATCH] dmaengine: at_hdmac: add DMA slave transfers From: Atsushi Nemoto In-Reply-To: <4A696449.7050303@atmel.com> References: <1248285885-1189-1-git-send-email-nicolas.ferre@atmel.com> <4A696449.7050303@atmel.com> X-Fingerprint: 6ACA 1623 39BD 9A94 9B1A B746 CA77 FE94 2874 D52F X-Pgp-Public-Key: http://wwwkeys.pgp.net/pks/lookup?op=get&search=0x2874D52F X-Mailer: Mew version 5.2 on Emacs 22.2 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1313 Lines: 30 On Fri, 24 Jul 2009 09:35:37 +0200, Nicolas Ferre wrote: > > Seems straightforward and self contained, applied. Just curious which > > drivers will take advantage of this slave capability? As it stands I > > do not see any in-tree users of at_hdmac beyond dmatest? > > Well, in fact the same as dw_dmac: atmel-mci. Adaptation of other > drivers are coming: probably ac97 and spi interfaces. > > The patches for adaptation of atmel-mci to at_hdmac are coming... Your atc_chain_complete() calls dma_unmap_xxx unless DMA_COMPL_SKIP_XXX_UNMAP specified. But atmel-mci driver does not set the flag on dma_async_tx_descriptor. I suppose one of them should be fixed. It is not clear for me how dma driver should handle unmapping on completion of slave DMA. Are there any consensus on it? I enclosed unmapping code of txx9dmac driver by "if (!slave)" and did not use DMA_COMPL_SKIP_XXX_UNMAP flag in its client driver (txx9aclc ASoC driver). If consensus made on how to handle unmapping on slave DMA, I will follow it. --- Atsushi Nemoto -- 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/