Re: [PATCH v3 2/2] mmc: dw_mmc: exynos: increase DMA threshold value for exynos7870

[Shawn Lin <shawn.lin@rock-chips.com>]

在 2026/04/15 星期三 23:02, Kaustabh Chakraborty 写道:
> Exynos 7870 compatible controllers, such as SDIO ones are not able to
> perform DMA transfers for small sizes of data (~16 to ~512 bytes),
> resulting in cache issues in subsequent transfers. Increase the DMA
> transfer threshold to 512 to allow the shorter transfers to take place,
> bypassing DMA.
> 

Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com>

> Signed-off-by: Kaustabh Chakraborty <kauschluss@disroot.org>
> ---
>   drivers/mmc/host/dw_mmc-exynos.c | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/mmc/host/dw_mmc-exynos.c b/drivers/mmc/host/dw_mmc-exynos.c
> index 261344d3a8cfe..4b76b997ddc15 100644
> --- a/drivers/mmc/host/dw_mmc-exynos.c
> +++ b/drivers/mmc/host/dw_mmc-exynos.c
> @@ -141,6 +141,7 @@ static int dw_mci_exynos_priv_init(struct dw_mci *host)
>   		priv->ctrl_type == DW_MCI_TYPE_EXYNOS7870_SMU) {
>   		/* Quirk needed for certain Exynos SoCs */
>   		host->quirks |= DW_MMC_QUIRK_FIFO64_32;
> +		host->dma_threshold = 512;
>   	}
>   
>   	if (priv->ctrl_type == DW_MCI_TYPE_ARTPEC8) {
>