Messages in this thread | | | Date | Sun, 03 Jun 2012 16:27:59 -0300 | From | "William F." <> | Subject | PLEASE, REMOVE MY EMAIL ADDRESS FROM ITS LIST. |
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Em 03-06-2012 16:09, Russell King - ARM Linux escreveu: > 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; >> +} > ______________________________________________________ > Linux MTD discussion mailing list > http://lists.infradead.org/mailman/listinfo/linux-mtd/ >
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