Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934313Ab3IDCCv (ORCPT ); Tue, 3 Sep 2013 22:02:51 -0400 Received: from va3ehsobe001.messaging.microsoft.com ([216.32.180.11]:1183 "EHLO va3outboundpool.messaging.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934213Ab3IDCCs (ORCPT ); Tue, 3 Sep 2013 22:02:48 -0400 X-Forefront-Antispam-Report: CIP:70.37.183.190;KIP:(null);UIP:(null);IPV:NLI;H:mail.freescale.net;RD:none;EFVD:NLI X-SpamScore: -6 X-BigFish: VS-6(zz98dI9371I103dK542I1432Izz1f42h208ch1ee6h1de0h1fdah2073h1202h1e76h1d1ah1d2ah1fc6hzz1de098h1de097h8275dhz2dh2a8h839h8e2h8e3h93fhd25hf0ah1288h12a5h12a9h12bdh137ah13b6h1441h1504h1537h153bh15d0h162dh1631h1758h18e1h1946h19b5h1ad9h1b0ah1b2fh1fb3h1d0ch1d2eh1d3fh1dfeh1dffh1e1dh1fe8h1ff5hbe9i1155h) From: Lu Jingchang-B35083 To: Vinod Koul CC: "shawn.guo@linaro.org" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "devicetree@vger.kernel.org" Subject: RE: [PATCH v4 3/3] dma: Add Freescale eDMA engine driver support Thread-Topic: [PATCH v4 3/3] dma: Add Freescale eDMA engine driver support Thread-Index: AQHOmk6HmvW+8Uz+BkmoowcYjqk1XpmqWYUAgAAO9YCAB5LmAIAAJBEQ///5soCAAA2oYIAAPxUAgAEsl2CAAGtJgIAA8Jiw Date: Wed, 4 Sep 2013 02:02:42 +0000 Message-ID: References: <1376633274-17850-1-git-send-email-b35083@freescale.com> <20130828081742.GC11414@intel.com> <20130902045050.GE7376@intel.com> <20130902063721.GK7376@intel.com> <20130902111200.GP7376@intel.com> <20130903113151.GE15824@intel.com> In-Reply-To: <20130903113151.GE15824@intel.com> Accept-Language: zh-CN, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.193.20.98] Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 X-OriginatorOrg: freescale.com X-FOPE-CONNECTOR: Id%0$Dn%*$RO%0$TLS%0$FQDN%$TlsDn% Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id r84230b9018841 Content-Length: 1513 Lines: 38 > -----Original Message----- > From: Vinod Koul [mailto:vinod.koul@intel.com] > Sent: Tuesday, September 03, 2013 7:32 PM > To: Lu Jingchang-B35083 > Cc: shawn.guo@linaro.org; linux-kernel@vger.kernel.org; linux-arm- > kernel@lists.infradead.org; devicetree@vger.kernel.org > Subject: Re: [PATCH v4 3/3] dma: Add Freescale eDMA engine driver support > > On Tue, Sep 03, 2013 at 05:43:21AM +0000, Lu Jingchang-B35083 wrote: > > Do you mean the DMA_SLAVE_CONFIG device_control? Yeah, the slave > driver could pass > > the slave_id. But the DMA_SLAVE_CONFIG may be called more than once, > and the eDMA > > driver just needs to set the slave id once for any given channel, after > that the > > transfer is transparent to the device. > It depends, for a channel requested, if you are only tranferring to a > particular > slave device then it can be confugured once. > so > 1. allocate channel > 2. dmaengine_slave_config() > > then you cnan do preare etc multiple times based on need. Yeah, I think we should just configure the slave id once and this would make the configuration simply. But by debugging, I find the dmaengine_slave_config() may be called more one times after requested by on user. So I put the slave id configuration in the channel request phase. And the effect is the same for exclusive channel. Thanks! Best Regards, Jingchang ????{.n?+???????+%?????ݶ??w??{.n?+????{??G?????{ay?ʇڙ?,j??f???h?????????z_??(?階?ݢj"???m??????G????????????&???~???iO???z??v?^?m???? ????????I?