From 16b492ce0a55735ed6f4c19ee9fb767badb3f19a Mon Sep 17 00:00:00 2001 From: Sergei Antonov Date: Fri, 10 Feb 2023 17:38:43 +0300 Subject: mmc: moxart: set maximum request/block/segment sizes Per datasheet: maximum block length is 2048 bytes, data length field is in bits 0-23 of the Data Length Register. Also for DMA mode we have to take into account rx/tx buffers' sizes. In my tests this change doubles SD card I/O performance on big files. Before the change Linux used default request size of 4 KB. Signed-off-by: Sergei Antonov Link: https://lore.kernel.org/r/20230210143843.369943-1-saproj@gmail.com Signed-off-by: Ulf Hansson --- drivers/mmc/host/moxart-mmc.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/mmc/host/moxart-mmc.c b/drivers/mmc/host/moxart-mmc.c index 52ed30f2d9f4..2d002c81dcf3 100644 --- a/drivers/mmc/host/moxart-mmc.c +++ b/drivers/mmc/host/moxart-mmc.c @@ -611,6 +611,9 @@ static int moxart_probe(struct platform_device *pdev) mmc->f_max = DIV_ROUND_CLOSEST(host->sysclk, 2); mmc->f_min = DIV_ROUND_CLOSEST(host->sysclk, CLK_DIV_MASK * 2); mmc->ocr_avail = 0xffff00; /* Support 2.0v - 3.6v power. */ + mmc->max_blk_size = 2048; /* Max. block length in REG_DATA_CONTROL */ + mmc->max_req_size = DATA_LEN_MASK; /* bits 0-23 in REG_DATA_LENGTH */ + mmc->max_blk_count = mmc->max_req_size / 512; if (IS_ERR(host->dma_chan_tx) || IS_ERR(host->dma_chan_rx)) { if (PTR_ERR(host->dma_chan_tx) == -EPROBE_DEFER || @@ -628,6 +631,8 @@ static int moxart_probe(struct platform_device *pdev) } dev_dbg(dev, "PIO mode transfer enabled\n"); host->have_dma = false; + + mmc->max_seg_size = mmc->max_req_size; } else { dev_dbg(dev, "DMA channels found (%p,%p)\n", host->dma_chan_tx, host->dma_chan_rx); @@ -646,6 +651,10 @@ static int moxart_probe(struct platform_device *pdev) cfg.src_addr = host->reg_phys + REG_DATA_WINDOW; cfg.dst_addr = 0; dmaengine_slave_config(host->dma_chan_rx, &cfg); + + mmc->max_seg_size = min3(mmc->max_req_size, + dma_get_max_seg_size(host->dma_chan_rx->device->dev), + dma_get_max_seg_size(host->dma_chan_tx->device->dev)); } if (readl(host->base + REG_BUS_WIDTH) & BUS_WIDTH_4_SUPPORT) -- cgit v1.2.3