Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757449AbbBENb1 (ORCPT ); Thu, 5 Feb 2015 08:31:27 -0500 Received: from mail-bl2on0061.outbound.protection.outlook.com ([65.55.169.61]:65145 "EHLO na01-bl2-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755960AbbBENbZ convert rfc822-to-8bit (ORCPT ); Thu, 5 Feb 2015 08:31:25 -0500 From: Appana Durga Kedareswara Rao To: Arnd Bergmann , "vinod.koul@intel.com" CC: "linux-arm-kernel@lists.infradead.org" , "devicetree@vger.kernel.org" , "vinod.koul@intel.com" , Srikanth Vemula , "linux-kernel@vger.kernel.org" , Srikanth Thokala , "dmaengine@vger.kernel.org" , "robh+dt@kernel.org" , Michal Simek , Anirudha Sarangi , "grant.likely@linaro.org" , "dan.j.williams@intel.com" , "Appana Durga Kedareswara Rao" Subject: RE: [PATCH v4] dma: Add Xilinx AXI Direct Memory Access Engine driver support Thread-Topic: [PATCH v4] dma: Add Xilinx AXI Direct Memory Access Engine driver support Thread-Index: AQHP6G+qFNHlEI1cgUeqDvA2b+1TW5w444MAgAFq8cCABQYD64B8/m2AgBtIbECACyOVIA== Date: Thu, 5 Feb 2015 13:31:18 +0000 References: <1413374436-14410-1-git-send-email-sthokal@xilinx.com> <3236720.MHeqOodrCV@wuerfel> <7dc11ef7ccec49bcb052c30b9aa916c3@BL2FFO11FD044.protection.gbl> <1967130.oYyZRWCcEF@wuerfel> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [172.23.97.163] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 X-RCIS-Action: ALLOW X-TM-AS-Product-Ver: IMSS-7.1.0.1224-7.5.0.1018-21304.007 X-TM-AS-User-Approved-Sender: Yes;Yes Message-ID: <68ff43bf48e24d7bb1fb36615c22f224@BL2FFO11FD007.protection.gbl> X-EOPAttributedMessage: 0 Authentication-Results: spf=pass (sender IP is 149.199.60.83) smtp.mailfrom=appana.durga.rao@xilinx.com; X-Forefront-Antispam-Report: CIP:149.199.60.83;CTRY:US;IPV:NLI;EFV:NLI;SFV:NSPM;SFS:(10009020)(6009001)(438002)(51704005)(377454003)(24454002)(104016003)(19300405004)(87936001)(6806004)(19580405001)(102836002)(92566002)(23726002)(92726002)(15975445007)(50466002)(47776003)(46406003)(74316001)(2656002)(19580395003)(86362001)(2501002)(46102003)(62966003)(106116001)(97756001)(77156002)(93886004)(54356999)(50986999)(53416004)(108616004)(76176999)(106466001)(2690400003)(107986001)(24736002)(562404015)(23106004);DIR:OUT;SFP:1101;SCL:1;SRVR:BL2FFO11HUB028;H:xsj-pvapsmtpgw01;FPR:;SPF:Pass;MLV:sfv;LANG:en; X-Microsoft-Antispam: UriScan:; X-Microsoft-Antispam: BCL:0;PCL:0;RULEID:;SRVR:BL2FFO11HUB028; X-Exchange-Antispam-Report-Test: UriScan:; X-Exchange-Antispam-Report-CFA-Test: BCL:0;PCL:0;RULEID:(601004);SRVR:BL2FFO11HUB028; X-Forefront-PRVS: 0478C23FE0 X-Exchange-Antispam-Report-CFA-Test: BCL:0;PCL:0;RULEID:;SRVR:BL2FFO11HUB028; X-OriginatorOrg: xilinx.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 05 Feb 2015 13:31:22.8616 (UTC) X-MS-Exchange-CrossTenant-Id: 657af505-d5df-48d0-8300-c31994686c5c X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=657af505-d5df-48d0-8300-c31994686c5c;Ip=[149.199.60.83] X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: BL2FFO11HUB028 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6029 Lines: 144 Ping ! > -----Original Message----- > From: Appana Durga Kedareswara Rao > Sent: Thursday, January 29, 2015 4:55 PM > To: 'Arnd Bergmann'; 'vinod.koul@intel.com' > Cc: 'linux-arm-kernel@lists.infradead.org'; 'devicetree@vger.kernel.org'; > 'vinod.koul@intel.com'; Srikanth Vemula; 'linux-kernel@vger.kernel.org'; > Srikanth Thokala; 'dmaengine@vger.kernel.org'; 'robh+dt@kernel.org'; > Michal Simek; Anirudha Sarangi; 'grant.likely@linaro.org'; > 'dan.j.williams@intel.com' > Subject: RE: [PATCH v4] dma: Add Xilinx AXI Direct Memory Access Engine > driver support > > Hi Vinod, > > > > -----Original Message----- > > From: Appana Durga Kedareswara Rao > > Sent: Monday, January 19, 2015 7:39 PM > > To: 'Arnd Bergmann'; vinod.koul@intel.com > > Cc: linux-arm-kernel@lists.infradead.org; devicetree@vger.kernel.org; > > vinod.koul@intel.com; Srikanth Vemula; linux-kernel@vger.kernel.org; > > Srikanth Thokala; dmaengine@vger.kernel.org; robh+dt@kernel.org; > > Michal Simek; Anirudha Sarangi; grant.likely@linaro.org; > > dan.j.williams@intel.com > > Subject: RE: [PATCH v4] dma: Add Xilinx AXI Direct Memory Access > > Engine driver support > > > > Hi Arnd, > > > > > -----Original Message----- > > > From: Arnd Bergmann [mailto:arnd@arndb.de] > > > Sent: Friday, October 24, 2014 7:29 PM > > > To: Appana Durga Kedareswara Rao > > > Cc: linux-arm-kernel@lists.infradead.org; > > > devicetree@vger.kernel.org; vinod.koul@intel.com; Srikanth Vemula; > > > linux-kernel@vger.kernel.org; Srikanth Thokala; > > > dmaengine@vger.kernel.org; robh+dt@kernel.org; Michal Simek; > > > Anirudha Sarangi; grant.likely@linaro.org; dan.j.williams@intel.com > > > Subject: Re: [PATCH v4] dma: Add Xilinx AXI Direct Memory Access > > > Engine driver support > > > > > > On Friday 24 October 2014 12:08:26 Appana Durga Kedareswara Rao > wrote: > > > > From: Arnd Bergmann [mailto:arnd@arndb.de] > > > > > On Tuesday 21 October 2014 09:06:13 Appana Durga Kedareswara Rao > > > wrote: > > > > > > The above mentioned API's and structures will be used by the > > > > > > dma test client driver's to set hardware configuration information. > > > > > > The dma client drivers are not mainlined yet and it is > > > > > > Internally used by our git-tree to test the DMA functionality > > > > > > in > > loopback . > > > > > > > > > > I would suggest you add the test driver into the main dmaengine > > > > > driver file directly then, so you don't need to export the symbols. > > > > > If there are important reasons to keep that as separate files, > > > > > just move the header to the drivers/dma/ directory and add the > > > > > test driver > > > there. > > > > > > > > Sorry I forgot to mention the below things in the mail .The Config > > > > API's and structures not only used by the dmaengine driver's but > > > > also used by the various IP's (Ex: Ethernet driver and SRIO > > > > driver these drivers are under development).For example the > > > > Ethernet driver is resides under drivers/net/ethernet but it needs > > > > to set some specific configuration parameters of the dma that's > > > > why created a separate header file for the h/w configurable > parameters. > > > > > > That is a bug in the ethernet driver, and we should not merge such code. > > > > > > Please fix those drivers before submitting them, so they don't rely > > > on additional interfaces beyond what the DMA engine API provides. > > > > > > If you need something that the common interface is missing, you can > > > send a patch to extend the dmaengine core driver, but more likely it > > > already does what you need and you are just not using it right. > > > > > > > Sorry for the delay in the reply. > > We need that header file in the include/linux/ directory for various > > reasons. > > > > As you know the Xilinx DMA's have a set of configurable parameters > > which we expect the DMA users to take advantage of. > > > > For example: > > For Axi DMA we have the following parameters that we expect to be > > commonly used. > > Coalesce count --> Used to configure the coalesce value. > > Delay timer ---> Used to set the delay value. > > > > We expect the Xilinx AXI Ethernet driver to use the Axi DMA driver in > > near furture. If so, using ethtool, we expect the driver users to play > > with the above parameters to do performance tuning. > > > > Hence AxiDMA driver must expose means to change coalese count or > > delay timer. > > > > Similarly For Axi VDMA we have the following parameters that will be > > used by the users of this driver. > > hsize --> Used to configure number of bytes per line. > > vsize -->Number of lines per frame. > > stride --> Number of bytes per line. > > > > > > Earlier in the driver we are embedding dma_slave_config into custom > > structs But Lars suggested to modify it. please refer to the below > > thread for more details. > > http://www.spinics.net/lists/dmaengine/msg00010.html > > > > And later we thought of creating a separate private member in > > dma_slave_config for sharing additional configuration between slave > > device and dma engine Or a new dma_ctrl_cmd like > > FSLDMA_EXTERNAL_START(http://www.kernelhub.org/?msg=405535&p=2 > ) > > > > Finally Vinod was ok with the existing suggestion so we dropped the > > above thought. > > > > @Vinod : Could you please comment on this. > > Ping ? > > Regards, > Kedar. > > > > > Regards, > > Kedar. > > > > > Arnd This email and any attachments are intended for the sole use of the named recipient(s) and contain(s) confidential information that may be proprietary, privileged or copyrighted under applicable law. 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