Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933862Ab2JWWmP (ORCPT ); Tue, 23 Oct 2012 18:42:15 -0400 Received: from mail-da0-f46.google.com ([209.85.210.46]:48591 "EHLO mail-da0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933719Ab2JWWmN (ORCPT ); Tue, 23 Oct 2012 18:42:13 -0400 MIME-Version: 1.0 In-Reply-To: <1350615088-14562-4-git-send-email-mporter@ti.com> References: <1350615088-14562-1-git-send-email-mporter@ti.com> <1350615088-14562-4-git-send-email-mporter@ti.com> From: Grant Likely Date: Tue, 23 Oct 2012 23:41:53 +0100 X-Google-Sender-Auth: EarQXUK61yLQlvJuL1lKjMV2ChU Message-ID: Subject: Re: [RFC PATCH 3/3] mmc: davinci: get SG segment limits with dma_get_channel_caps() To: Matt Porter Cc: Vinod Koul , Dan Williams , Chris Ball , Linux DaVinci Kernel List , Linux Kernel Mailing List , Linux MMC List Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7139 Lines: 170 On Fri, Oct 19, 2012 at 3:51 AM, Matt Porter wrote: > Replace the hardcoded values used to set max_segs/max_seg_size with > a dma_get_channel_caps() query to the dmaengine driver. > > Signed-off-by: Matt Porter Series looks reasonable to me. Reviewed-by: Grant Likely > --- > drivers/mmc/host/davinci_mmc.c | 66 +++++++++-------------------- > include/linux/platform_data/mmc-davinci.h | 3 -- > 2 files changed, 21 insertions(+), 48 deletions(-) > > diff --git a/drivers/mmc/host/davinci_mmc.c b/drivers/mmc/host/davinci_mmc.c > index f5d46ea..d1efacc 100644 > --- a/drivers/mmc/host/davinci_mmc.c > +++ b/drivers/mmc/host/davinci_mmc.c > @@ -145,18 +145,6 @@ > /* MMCSD Init clock in Hz in opendrain mode */ > #define MMCSD_INIT_CLOCK 200000 > > -/* > - * One scatterlist dma "segment" is at most MAX_CCNT rw_threshold units, > - * and we handle up to MAX_NR_SG segments. MMC_BLOCK_BOUNCE kicks in only > - * for drivers with max_segs == 1, making the segments bigger (64KB) > - * than the page or two that's otherwise typical. nr_sg (passed from > - * platform data) == 16 gives at least the same throughput boost, using > - * EDMA transfer linkage instead of spending CPU time copying pages. > - */ > -#define MAX_CCNT ((1 << 16) - 1) > - > -#define MAX_NR_SG 16 > - > static unsigned rw_threshold = 32; > module_param(rw_threshold, uint, S_IRUGO); > MODULE_PARM_DESC(rw_threshold, > @@ -217,8 +205,6 @@ struct mmc_davinci_host { > u8 version; > /* for ns in one cycle calculation */ > unsigned ns_in_one_cycle; > - /* Number of sg segments */ > - u8 nr_sg; > #ifdef CONFIG_CPU_FREQ > struct notifier_block freq_transition; > #endif > @@ -422,16 +408,7 @@ static int mmc_davinci_send_dma_request(struct mmc_davinci_host *host, > int ret = 0; > > if (host->data_dir == DAVINCI_MMC_DATADIR_WRITE) { > - struct dma_slave_config dma_tx_conf = { > - .direction = DMA_MEM_TO_DEV, > - .dst_addr = host->mem_res->start + DAVINCI_MMCDXR, > - .dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES, > - .dst_maxburst = > - rw_threshold / DMA_SLAVE_BUSWIDTH_4_BYTES, > - }; > chan = host->dma_tx; > - dmaengine_slave_config(host->dma_tx, &dma_tx_conf); > - > desc = dmaengine_prep_slave_sg(host->dma_tx, > data->sg, > host->sg_len, > @@ -444,16 +421,7 @@ static int mmc_davinci_send_dma_request(struct mmc_davinci_host *host, > goto out; > } > } else { > - struct dma_slave_config dma_rx_conf = { > - .direction = DMA_DEV_TO_MEM, > - .src_addr = host->mem_res->start + DAVINCI_MMCDRR, > - .src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES, > - .src_maxburst = > - rw_threshold / DMA_SLAVE_BUSWIDTH_4_BYTES, > - }; > chan = host->dma_rx; > - dmaengine_slave_config(host->dma_rx, &dma_rx_conf); > - > desc = dmaengine_prep_slave_sg(host->dma_rx, > data->sg, > host->sg_len, > @@ -1166,6 +1134,7 @@ static int __init davinci_mmcsd_probe(struct platform_device *pdev) > struct resource *r, *mem = NULL; > int ret = 0, irq = 0; > size_t mem_size; > + struct dmaengine_chan_caps *dma_chan_caps; > > /* REVISIT: when we're fully converted, fail if pdata is NULL */ > > @@ -1215,12 +1184,6 @@ static int __init davinci_mmcsd_probe(struct platform_device *pdev) > > init_mmcsd_host(host); > > - if (pdata->nr_sg) > - host->nr_sg = pdata->nr_sg - 1; > - > - if (host->nr_sg > MAX_NR_SG || !host->nr_sg) > - host->nr_sg = MAX_NR_SG; > - > host->use_dma = use_dma; > host->mmc_irq = irq; > host->sdio_irq = platform_get_irq(pdev, 1); > @@ -1249,14 +1212,27 @@ static int __init davinci_mmcsd_probe(struct platform_device *pdev) > mmc->caps |= pdata->caps; > mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34; > > - /* With no iommu coalescing pages, each phys_seg is a hw_seg. > - * Each hw_seg uses one EDMA parameter RAM slot, always one > - * channel and then usually some linked slots. > - */ > - mmc->max_segs = MAX_NR_SG; > + { > + struct dma_slave_config dma_txrx_conf = { > + .src_addr = host->mem_res->start + DAVINCI_MMCDRR, > + .src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES, > + .src_maxburst = > + rw_threshold / DMA_SLAVE_BUSWIDTH_4_BYTES, > + .dst_addr = host->mem_res->start + DAVINCI_MMCDXR, > + .dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES, > + .dst_maxburst = > + rw_threshold / DMA_SLAVE_BUSWIDTH_4_BYTES, > + }; > + dmaengine_slave_config(host->dma_tx, &dma_txrx_conf); > + dmaengine_slave_config(host->dma_rx, &dma_txrx_conf); > + } > > - /* EDMA limit per hw segment (one or two MBytes) */ > - mmc->max_seg_size = MAX_CCNT * rw_threshold; > + /* Just check one channel for the DMA SG limits */ > + dma_chan_caps = dma_get_channel_caps(host->dma_tx, DMA_MEM_TO_DEV); > + if (dma_chan_caps) { > + mmc->max_segs = dma_chan_caps->seg_nr; > + mmc->max_seg_size = dma_chan_caps->seg_len; > + } > > /* MMC/SD controller limits for multiblock requests */ > mmc->max_blk_size = 4095; /* BLEN is 12 bits */ > diff --git a/include/linux/platform_data/mmc-davinci.h b/include/linux/platform_data/mmc-davinci.h > index 5ba6b22..6910209 100644 > --- a/include/linux/platform_data/mmc-davinci.h > +++ b/include/linux/platform_data/mmc-davinci.h > @@ -25,9 +25,6 @@ struct davinci_mmc_config { > > /* Version of the MMC/SD controller */ > u8 version; > - > - /* Number of sg segments */ > - u8 nr_sg; > }; > void davinci_setup_mmc(int module, struct davinci_mmc_config *config); > > -- > 1.7.9.5 > > -- > 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/ -- Grant Likely, B.Sc., P.Eng. Secret Lab Technologies Ltd. -- 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/