On Fri, Dec 15, 2023 at 05:17:47PM +0530, Thangaraj Samynathan wrote:
> + tx_dma_addr = dma_map_single(dev, (void *)xfer->tx_buf, xfer->len, DMA_TO_DEVICE);
> + if (dma_mapping_error(NULL, tx_dma_addr)) {
> + tx_dma_addr = 0;
> + ret = -ENOMEM;
> + goto error;
> + }
The core can do all the DMA mapping for you if you provide a can_dma()
operation, this supports switching between DMA and non-DMA modes per
transfer - often you'll get better performance from PIO for smaller
lengths due to the overhead of setting up DMA and taking the interrupt
on completion.
Attachment:
signature.asc
Description: PGP signature
