Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754176Ab2FCTJz (ORCPT ); Sun, 3 Jun 2012 15:09:55 -0400 Received: from caramon.arm.linux.org.uk ([78.32.30.218]:50050 "EHLO caramon.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751218Ab2FCTJy (ORCPT ); Sun, 3 Jun 2012 15:09:54 -0400 Date: Sun, 3 Jun 2012 20:09:32 +0100 From: Russell King - ARM Linux To: Roland Stigge Cc: linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, devicetree-discuss@lists.ozlabs.org, dwmw2@infradead.org, kevin.wells@nxp.com, srinivas.bakki@nxp.com, linux-arm-kernel@lists.infradead.org, hechtb@googlemail.com, lars@metafoo.de, b32955@freescale.com, leiwen@marvell.com, dedekind1@gmail.com Subject: Re: [PATCH v4] MTD: LPC32xx SLC NAND driver Message-ID: <20120603190932.GB23368@n2100.arm.linux.org.uk> References: <1338748689-29645-1-git-send-email-stigge@antcom.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1338748689-29645-1-git-send-email-stigge@antcom.de> User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2457 Lines: 71 On Sun, Jun 03, 2012 at 08:38:09PM +0200, Roland Stigge wrote: > +static int lpc32xx_xmit_dma(struct mtd_info *mtd, dma_addr_t dma, > + void *mem, int len, enum dma_transfer_direction dir) > +{ > + struct nand_chip *chip = mtd->priv; > + struct lpc32xx_nand_host *host = chip->priv; > + struct dma_async_tx_descriptor *desc; > + int flags = DMA_CTRL_ACK | DMA_PREP_INTERRUPT; > + int res; > + dma_cookie_t cookie; > + > + host->dma_slave_config.direction = dir; > + host->dma_slave_config.src_addr = dma; > + host->dma_slave_config.dst_addr = dma; > + host->dma_slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; > + host->dma_slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; > + host->dma_slave_config.src_maxburst = 4; > + host->dma_slave_config.dst_maxburst = 4; > + /* DMA controller does flow control: */ > + host->dma_slave_config.device_fc = false; > + if (dmaengine_slave_config(host->dma_chan, &host->dma_slave_config)) { > + dev_err(mtd->dev.parent, "Failed to setup DMA slave\n"); > + return -ENXIO; > + } > + > + sg_init_one(&host->sgl, mem, len); > + > + res = dma_map_sg(host->dma_chan->device->dev, &host->sgl, 1, > + DMA_BIDIRECTIONAL); > + if (res != 1) { > + dev_err(mtd->dev.parent, "Failed to map sg list\n"); > + return -ENXIO; > + } > + desc = dmaengine_prep_slave_sg(host->dma_chan, &host->sgl, 1, dir, > + flags); > + if (!desc) { > + dev_err(mtd->dev.parent, "Failed to prepare slave sg\n"); > + goto out1; > + } > + > + init_completion(&host->comp); > + desc->callback = lpc32xx_dma_complete_func; > + desc->callback_param = &host->comp; > + > + cookie = dmaengine_submit(desc); > + if (dma_submit_error(cookie)) { > + dev_err(mtd->dev.parent, "Failed to dmaengine_submit()\n"); > + goto out1; > + } dmaengine_submit() is no longer allowed to fail, so you don't need this check here anymore. It's been that way for a long time. > + dma_async_issue_pending(host->dma_chan); > + > + wait_for_completion_timeout(&host->comp, msecs_to_jiffies(1000)); What about unmapping the buffer upon completion? > + > + return 0; > +out1: > + dma_unmap_sg(host->dma_chan->device->dev, &host->sgl, 1, > + DMA_BIDIRECTIONAL); > + return -ENXIO; > +} -- 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/