From patchwork Fri Jan 11 05:48:45 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matt Porter X-Patchwork-Id: 1963751 Return-Path: X-Original-To: patchwork-spi-devel-general@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from lists.sourceforge.net (lists.sourceforge.net [216.34.181.88]) by patchwork1.kernel.org (Postfix) with ESMTP id 5E7CC3FF0F for ; Fri, 11 Jan 2013 05:44:50 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=sfs-ml-2.v29.ch3.sourceforge.com) by sfs-ml-2.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1TtXQA-0006CY-2h; Fri, 11 Jan 2013 05:44:50 +0000 Received: from sog-mx-2.v43.ch3.sourceforge.com ([172.29.43.192] helo=mx.sourceforge.net) by sfs-ml-2.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1TtXQ8-0006CM-6X for spi-devel-general@lists.sourceforge.net; Fri, 11 Jan 2013 05:44:48 +0000 Received-SPF: pass (sog-mx-2.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.216.51 as permitted sender) client-ip=209.85.216.51; envelope-from=ohiomdp@gmail.com; helo=mail-qa0-f51.google.com; Received: from mail-qa0-f51.google.com ([209.85.216.51]) by sog-mx-2.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1TtXQ7-0008H3-33 for spi-devel-general@lists.sourceforge.net; Fri, 11 Jan 2013 05:44:48 +0000 Received: by mail-qa0-f51.google.com with SMTP id i20so1229405qad.17 for ; Thu, 10 Jan 2013 21:44:41 -0800 (PST) X-Received: by 10.224.31.209 with SMTP id z17mr59808086qac.28.1357883081682; Thu, 10 Jan 2013 21:44:41 -0800 (PST) Received: from beef.ohporter.com (cpe-24-166-64-7.neo.res.rr.com. [24.166.64.7]) by mx.google.com with ESMTPS id ds8sm1897114qab.18.2013.01.10.21.44.38 (version=TLSv1.1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 10 Jan 2013 21:44:40 -0800 (PST) From: Matt Porter To: Tony Lindgren , Sekhar Nori , Grant Likely , Mark Brown , Benoit Cousson , Russell King , Vinod Koul , Rob Landley , Chris Ball Subject: [PATCH v4 09/14] mmc: omap_hsmmc: set max_segs based on dma engine limitations Date: Fri, 11 Jan 2013 00:48:45 -0500 Message-Id: <1357883330-5364-10-git-send-email-mporter@ti.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1357883330-5364-1-git-send-email-mporter@ti.com> References: <1357883330-5364-1-git-send-email-mporter@ti.com> X-Spam-Score: 1.4 (+) X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. 2.9 KHOP_BIG_TO_CC Sent to 10+ recipients instaed of Bcc or a list -1.5 SPF_CHECK_PASS SPF reports sender host as permitted sender for sender-domain 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 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 X-Headers-End: 1TtXQ7-0008H3-33 Cc: Linux DaVinci Kernel List , Arnd Bergmann , Linux Documentation List , Devicetree Discuss , Linux MMC List , Linux Kernel Mailing List , Rob Herring , Dan Williams , Linux SPI Devel List , Linux OMAP List , Linux ARM Kernel List X-BeenThere: spi-devel-general@lists.sourceforge.net X-Mailman-Version: 2.1.9 Precedence: list List-Id: Linux SPI core/device drivers discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: spi-devel-general-bounces@lists.sourceforge.net 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_channel_caps() API. If the nr_segs capability 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 | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c index e79b12d..f74bd69 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 dmaengine_chan_caps *dma_chan_caps; struct pinctrl *pinctrl; match = of_match_device(of_match_ptr(omap_mmc_of_match), &pdev->dev); @@ -1935,6 +1936,11 @@ static int omap_hsmmc_probe(struct platform_device *pdev) goto err_irq; } + /* Some DMA Engines only handle a limited number of SG segments */ + dma_chan_caps = dma_get_channel_caps(host->rx_chan, DMA_DEV_TO_MEM); + if (dma_chan_caps && dma_chan_caps->seg_nr) + mmc->max_segs = dma_chan_caps->seg_nr; + /* Request IRQ for MMC operations */ ret = request_irq(host->irq, omap_hsmmc_irq, 0, mmc_hostname(mmc), host);