From patchwork Thu Mar 7 04:16:38 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matt Porter X-Patchwork-Id: 2230111 Return-Path: X-Original-To: patchwork-linux-mmc@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork1.kernel.org (Postfix) with ESMTP id A614E40077 for ; Thu, 7 Mar 2013 04:16:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932434Ab3CGEQd (ORCPT ); Wed, 6 Mar 2013 23:16:33 -0500 Received: from mail-ia0-f171.google.com ([209.85.210.171]:40374 "EHLO mail-ia0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756931Ab3CGEQM (ORCPT ); Wed, 6 Mar 2013 23:16:12 -0500 Received: by mail-ia0-f171.google.com with SMTP id z13so39104iaz.30 for ; Wed, 06 Mar 2013 20:16:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=x-received:sender:from:to:cc:subject:date:message-id:x-mailer :in-reply-to:references; bh=GF/ImxCs5Tuk3M4hVBVA5w49oN/zYwITYVdkIS4JXXM=; b=Z+R00kEYuGfHMQETcfR0Z9573ehZnSRrt8bUN2bbhMwKv9fxehA0rjCHuc3+iLCYrd kHpe5aaongT5/xrp4tItfbWivHz6MAy1Pzo4eB0bNZl7NDelcYFr8ux2AvfwbKizYEca nXmdgb4l7pd1+FdE3owFVm0zl2Y5srORn9apfOAIrhfODjN0JnX89KNCPXJaZjyp8uvn bjo78x68GPJBrf5Gedj2r1Zie0oaC3CozHTlzW9KglykCvbAsTJjBrLPVbaGCCfMY8Ru qG7ekf4OV4QdhtEkyHR6pZ1hxsl4H254lytONsBDmejDW8SRMd68iMCW3llOJy6Hy86R LTWg== X-Received: by 10.42.54.5 with SMTP id p5mr33465536icg.49.1362629771754; Wed, 06 Mar 2013 20:16:11 -0800 (PST) Received: from beef.ohporter.com (cpe-98-27-254-98.neo.res.rr.com. [98.27.254.98]) by mx.google.com with ESMTPS id gy3sm94024igc.10.2013.03.06.20.16.10 (version=TLSv1.1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 06 Mar 2013 20:16:11 -0800 (PST) From: Matt Porter To: Balaji T K , Chris Ball , Benoit Cousson , Tony Lindgren , Russell King Cc: Devicetree Discuss , Linux ARM Kernel List , Linux OMAP List , Linux Kernel Mailing List , Linux MMC List Subject: [PATCH 1/2] mmc: omap_hsmmc: set max_segs based on dma engine limits Date: Wed, 6 Mar 2013 23:16:38 -0500 Message-Id: <1362629799-22485-2-git-send-email-mporter@ti.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1362629799-22485-1-git-send-email-mporter@ti.com> References: <1362629799-22485-1-git-send-email-mporter@ti.com> Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org The EDMA DMAC has a hardware limitation that prevents supporting scatter gather lists with any number of segments. The DMA Engine API reports the maximum number of segments a channel can support via the optional dma_get_slave_sg_limits() API. If the max_nr_segs limit is present, the value is used to configure mmc->max_segs appropriately. Signed-off-by: Matt Porter Acked-by: Tony Lindgren --- drivers/mmc/host/omap_hsmmc.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c index e79b12d..f74d2ef 100644 --- a/drivers/mmc/host/omap_hsmmc.c +++ b/drivers/mmc/host/omap_hsmmc.c @@ -1769,6 +1769,7 @@ static int omap_hsmmc_probe(struct platform_device *pdev) const struct of_device_id *match; dma_cap_mask_t mask; unsigned tx_req, rx_req; + struct dma_slave_sg_limits *dma_sg_limits; struct pinctrl *pinctrl; match = of_match_device(of_match_ptr(omap_mmc_of_match), &pdev->dev); @@ -1935,6 +1936,13 @@ static int omap_hsmmc_probe(struct platform_device *pdev) goto err_irq; } + /* Some DMA Engines only handle a limited number of SG segments */ + dma_sg_limits = dma_get_slave_sg_limits(host->rx_chan, + DMA_SLAVE_BUSWIDTH_4_BYTES, + mmc->max_blk_size / 4); + if (dma_sg_limits && dma_sg_limits->max_seg_nr) + mmc->max_segs = dma_sg_limits->max_seg_nr; + /* Request IRQ for MMC operations */ ret = request_irq(host->irq, omap_hsmmc_irq, 0, mmc_hostname(mmc), host);