On Thu, Feb 18, 2021 at 04:21:26PM +0100, Thomas Zimmermann wrote: > Sure, it's at [1]. For udl, the dmabuf would need to be in system memory. > The driver creates urbs from the framebuffer content and sends them to the > device for displaying. > > My question is more: what's the best interface to do this? Is there example > code somewhere?
URBs do point to system memory most of the time. I'm not a real USB expert, but usb-storage or uas would be classic examples for drivers that take arbitrary memory controller by another layer and do DMA to/from that.
