diff mbox series

mmc: moxart: set maximum request/block/segment sizes

Message ID 20230210143843.369943-1-saproj@gmail.com (mailing list archive)
State New, archived
Headers show
Series mmc: moxart: set maximum request/block/segment sizes | expand

Commit Message

Sergei Antonov Feb. 10, 2023, 2:38 p.m. UTC
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 <saproj@gmail.com>
---
 drivers/mmc/host/moxart-mmc.c | 9 +++++++++
 1 file changed, 9 insertions(+)

Comments

Ulf Hansson Feb. 14, 2023, 12:18 p.m. UTC | #1
On Fri, 10 Feb 2023 at 15:38, Sergei Antonov <saproj@gmail.com> wrote:
>
> 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 <saproj@gmail.com>

Applied for next, thanks!

Kind regards
Uffe


> ---
>  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)
> --
> 2.34.1
>
diff mbox series

Patch

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)