On Sun, Feb 20, 2022 at 04:40:44PM +0800, Baoquan He wrote:

On 02/19/22 at 08:17am, Christoph Hellwig wrote:

quoted

On Sat, Feb 19, 2022 at 08:52:20AM +0800, Baoquan He wrote:

quoted

 	if (request_dma(dma, DRIVER_NAME))
 		goto err;
 
+	dma_set_mask_and_coherent(mmc_dev(host->mmc), DMA_BIT_MASK(24));

This also sets the streaming mask, but the driver doesn't seem to make
use of that.  Please document it in the commit log.

Thanks for reviewing. I will change it to dma_set_mask(), and describe
this change in patch log.

No, if you change it, it should be dma_set_coherent_mask only as it is
not using streaming mappings.  I suspect dma_set_mask_and_coherent is
the right thing if the driver ever wants to use streaming mapping,
it would just need to be documented in the commit message.