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. Also setting smaller than 32 bit masks can fail, so this should have error handling.