On Sun, Feb 20, 2022 at 04:40:44PM +0800, Baoquan He wrote: > On 02/19/22 at 08:17am, Christoph Hellwig wrote: > > On Sat, Feb 19, 2022 at 08:52:20AM +0800, Baoquan He wrote: > > > 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.