On Oct 31 Julian Calaby wrote: > Hi, > > On Mon, Oct 31, 2011 at 12:53, yoma sophian <sophian.yoma@xxxxxxxxx> wrote: > > hi stefan: > > Thanks for your reply. > > 2011/10/30, Stefan Richter <stefanr@xxxxxxxxxxxxxxxxx>: > >> The low level driver, not SCSI core, is responsible to obtain a DMA > >> address. > > > > Why I ask this because I found there is no same transformation for > > scsi usb subsystem. > > Would anyone can let me know where it is? > > I am not familiar with the code in question, but I would guess that > this would happen in the USB Controller Interface driver. I don't know the USB subsystem either. Anyway, in this case the "SCSI low-level" (i.e. SCSI transport and interconnect driver) internally consists of USB high-level (storage), USB core, and USB low-level (UHCI, EHCI or whatever). "grep -r dma_map_sg drivers/usb/" shows occurrences of scatter-gather list DMA mappings in the USB core. I haven't checked whether these are indeed the ones that the usb-storage driver relies on. -- Stefan Richter -=====-==-== =-=- ===== http://arcgraph.de/sr/ -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
