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: 2230201 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by patchwork1.kernel.org (Postfix) with ESMTP id 09A343FCF6 for ; Thu, 7 Mar 2013 04:20:38 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1UDSG9-0001AQ-4a; Thu, 07 Mar 2013 04:16:49 +0000 Received: from mail-ie0-x22a.google.com ([2607:f8b0:4001:c03::22a]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1UDSFY-0000xo-NC for linux-arm-kernel@lists.infradead.org; Thu, 07 Mar 2013 04:16:14 +0000 Received: by mail-ie0-f170.google.com with SMTP id c11so57498ieb.15 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 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> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130306_231613_511916_AC597DF9 X-CRM114-Status: GOOD ( 12.67 ) X-Spam-Score: -1.9 (-) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-1.9 points) pts rule name description ---- ---------------------- -------------------------------------------------- 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (ohiomdp[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature Cc: Devicetree Discuss , Linux OMAP List , Linux MMC List , Linux Kernel Mailing List , Linux ARM Kernel List X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.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);