Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754035Ab2HZW1L (ORCPT ); Sun, 26 Aug 2012 18:27:11 -0400 Received: from bosmailout14.eigbox.net ([66.96.185.14]:45041 "EHLO bosmailout14.eigbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753318Ab2HZW1J (ORCPT ); Sun, 26 Aug 2012 18:27:09 -0400 X-Authority-Analysis: v=2.0 cv=aPZHX8Bm c=1 sm=1 a=OWwsRfqG41DA94+gJvZMBg==:17 a=bc2JKO6qiGsA:10 a=kfTud4QeKxsA:10 a=PnNOxYUqSyIA:10 a=8nJEP1OIZ-IA:10 a=EqYlCx_eqd0A:10 a=bJ0fqD8TFZgqkSadqForXVIPBlU=:19 a=D19gQVrFAAAA:8 a=XEr1Jo0RWYtCeQoAj2QA:9 a=wPNLvfGTeEIA:10 a=6uKCkKhFq2wXOH2GoQX8aA==:117 X-EN-OrigOutIP: 10.20.18.3 X-EN-IMPSID: rZm21j01z03yW7601Zm3Z2 Message-ID: <503A89E0.40602@yahoo.es> Date: Mon, 27 Aug 2012 04:41:04 +0800 From: Hein Tibosch User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:14.0) Gecko/20120713 Thunderbird/14.0 MIME-Version: 1.0 To: viresh kumar CC: spear-devel , Linux Kernel Mailing List , "ludovic.desroches" , Havard Skinnemoen , Nicolas Ferre , egtvedt@samfundet.no, Andrew Morton , Arnd Bergmann Subject: [PATCH 2/2] dw_dmac: max_mem_width limits value for SRC/DST_TR_WID register Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-EN-UserInfo: 3946c951b80c12a8be5482963a0b1232:e0ae43bc192b431f8b69f09a37527cbc X-EN-AuthUser: hein@htibosch.net X-EN-OrigIP: 114.79.63.241 X-EN-OrigHost: unknown Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2400 Lines: 74 The dw_dmac driver was earlier adapted to do 64-bit transfers on the memory side (https://lkml.org/lkml/2012/1/18/52) This works on ARM platforms but for AVR32 (AP700x) the maximum allowed transfer size is 32-bits. This patch allows the arch to set a new slave property max_mem_width to limit the size. Allowable values for dw_dma_slave::max_mem_width are: 0 : leave it up to dw_dmac (64 bits) 1 : 16-bits 2 : 32-bits Signed-off-by: Hein Tibosch --- drivers/dma/dw_dmac.c | 8 ++++++++ include/linux/dw_dmac.h | 3 +++ 2 files changed, 11 insertions(+), 0 deletions(-) diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c index 7212961..a4bdf1d 100644 --- a/drivers/dma/dw_dmac.c +++ b/drivers/dma/dw_dmac.c @@ -754,6 +754,10 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, mem_width = 1; else mem_width = 0; + /* Some controllers don't support 64-bits mem access */ + if (dws->max_mem_width && + mem_width > dws->max_mem_width) + mem_width = dws->max_mem_width; slave_sg_todev_fill_desc: desc = dwc_desc_get(dwc); @@ -821,6 +825,10 @@ slave_sg_todev_fill_desc: mem_width = 1; else mem_width = 0; + /* Some controllers don't support 64-bits mem access */ + if (dws->max_mem_width && + mem_width > dws->max_mem_width) + mem_width = dws->max_mem_width; slave_sg_fromdev_fill_desc: desc = dwc_desc_get(dwc); diff --git a/include/linux/dw_dmac.h b/include/linux/dw_dmac.h index 2412e02..60b01c3 100644 --- a/include/linux/dw_dmac.h +++ b/include/linux/dw_dmac.h @@ -51,6 +51,8 @@ enum dw_dma_msize { * @cfg_lo: Platform-specific initializer for the CFG_LO register * @src_master: src master for transfers on allocated channel. * @dst_master: dest master for transfers on allocated channel. + * @max_mem_width: max value for SRC/DST_TR_WIDTH register + * default 0 means: leave it up to driver */ struct dw_dma_slave { struct device *dma_dev; @@ -58,6 +60,7 @@ struct dw_dma_slave { u32 cfg_lo; u8 src_master; u8 dst_master; + u8 max_mem_width; }; /* Platform-configurable bits in CFG_HI */ -- 1.7.8.0 -- 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/