[PATCH v4 1/1] mmc: use dmaengine_get_dma_device() instead of chan->device->dev

[Arnd Bergmann]

On Wed, Sep 23, 2026, at 20:45, Frank.Li at oss.nxp.com wrote:
> @@ -214,7 +214,7 @@ config MMC_SDHCI_OF_AT91
>  config MMC_SDHCI_OF_ESDHC
>  	tristate "SDHCI OF support for the Freescale eSDHC controller"
>  	depends on MMC_SDHCI_PLTFM
> -	depends on PPC || ARCH_MXC || ARCH_LAYERSCAPE || COMPILE_TEST
> +	depends on PPC || ARCHMXC || ARCH_LAYERSCAPE || COMPILE_TEST
>  	select MMC_SDHCI_IO_ACCESSORS
>  	select FSL_GUTS

This looks like an accidental bug that should be removed from the patch.

> @@ -961,7 +961,7 @@ static void atmci_dma_cleanup(struct atmel_mci *host)
>  	struct mmc_data                 *data = host->data;
> 
>  	if (data)
> -		dma_unmap_sg(host->dma.chan->device->dev,
> +		dma_unmap_sg(dmaengine_get_dma_device(host->dma.chan),
>  				data->sg, data->sg_len,
>  				mmc_get_dma_dir(data));

Since you have the exact construct in a lot of drivers, would
it make sense to take this one step further and introduce
a new set of helpers in drivers/dma/dmaengine.h, such as

unsigned int dmaengine_map_sg(struct dma_chan *chan, struct scatterlist *sg, ...);

      Arnd