Linux Renesas SOC kernel development
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From: Ulrich Hecht <uli@fpond.eu>
To: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>,
	linux-renesas-soc@vger.kernel.org
Subject: Re: [PATCH RFC 4/4] mmc: host: renesas_sdhi_sys_dmac: Set dma_buswidth value to 32 byte
Date: Tue, 26 Nov 2019 11:46:15 +0100 (CET)	[thread overview]
Message-ID: <173522043.1354245.1574765175403@webmail.strato.com> (raw)
In-Reply-To: <1574403231-18512-5-git-send-email-yoshihiro.shimoda.uh@renesas.com>


> On November 22, 2019 at 7:13 AM Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> wrote:
> 
> 
> To improve performance, this patch sets dma_buswidth value to 32
> when transfer size is multiples of 32. In other words, a sd card
> transfer's size if not multiples of 32, this driver uses PIO
> and then the performance will be down.
> 
> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> ---
>  drivers/mmc/host/renesas_sdhi_sys_dmac.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/mmc/host/renesas_sdhi_sys_dmac.c b/drivers/mmc/host/renesas_sdhi_sys_dmac.c
> index 09137cc..65e71b6 100644
> --- a/drivers/mmc/host/renesas_sdhi_sys_dmac.c
> +++ b/drivers/mmc/host/renesas_sdhi_sys_dmac.c
> @@ -58,7 +58,7 @@ static const struct renesas_sdhi_of_data of_rcar_gen2_compatible = {
>  	.capabilities	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ |
>  			  MMC_CAP_CMD23,
>  	.capabilities2	= MMC_CAP2_NO_WRITE_PROTECT,
> -	.dma_buswidth	= DMA_SLAVE_BUSWIDTH_4_BYTES,
> +	.dma_buswidth	= DMA_SLAVE_BUSWIDTH_32_BYTES,
>  	.dma_rx_offset	= 0x2000,
>  	.scc_offset	= 0x0300,
>  	.taps		= rcar_gen2_scc_taps,
> -- 
> 2.7.4
>

Reviewed-by: Ulrich Hecht <uli+renesas@fpond.eu>

CU
Uli

  reply	other threads:[~2019-11-26 10:52 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-22  6:13 [PATCH RFC 0/4] mmc: host: renesas_sdhi_sys_dmac: change dma_buswidth Yoshihiro Shimoda
2019-11-22  6:13 ` [PATCH RFC 1/4] mmc: host: renesas_sdhi_sys_dmac: Use dma_buswidth instead of hardcoded value Yoshihiro Shimoda
2019-11-26 10:45   ` Ulrich Hecht
2019-11-22  6:13 ` [PATCH RFC 2/4] mmc: host: renesas_sdhi_sys_dmac: Do not fall back to PIO Yoshihiro Shimoda
2019-11-26 10:45   ` Ulrich Hecht
2019-11-22  6:13 ` [PATCH RFC 3/4] mmc: host: renesas_sdhi_sys_dmac: add DMACR setting Yoshihiro Shimoda
2019-11-26 10:46   ` Ulrich Hecht
2019-12-02  8:19     ` Yoshihiro Shimoda
2019-11-22  6:13 ` [PATCH RFC 4/4] mmc: host: renesas_sdhi_sys_dmac: Set dma_buswidth value to 32 byte Yoshihiro Shimoda
2019-11-26 10:46   ` Ulrich Hecht [this message]
2019-11-28 21:07   ` Wolfram Sang
2019-12-02  8:38     ` Yoshihiro Shimoda
2019-12-02  8:54       ` Wolfram Sang
2019-11-26 10:45 ` [PATCH RFC 0/4] mmc: host: renesas_sdhi_sys_dmac: change dma_buswidth Ulrich Hecht
2019-12-02  8:09   ` Yoshihiro Shimoda

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