On Tue, 15 Dec 2009, Matthieu CASTET wrote: > Hi, > > > I am wondering about using dma with gadget. > > From what I understand gadget function can put anything in req->buf. > That is the case for u_ether that puts skb->data. > > But if the driver wants to do dma they need a buffer aligned on a cache > boundary (to clean/invalidate/flush buffer). > > Who should do the job ? > - Gadget function should provide "provide DMA-safe buffers" like in spi > subsystem ? > - Driver need to copy the data in a safe buffer. Buffers should be allocated by calling kmalloc() or equivalent functions. These routines always return addresses that are cacheline-aligned on architectures which require it. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
