On 21-01-14 13:00:21, Alan Stern wrote: > On Thu, Jan 14, 2021 at 01:04:02PM +0800, Peter Chen wrote: > > On 21-01-14 11:59:07, Daewoong Kim wrote: > > > DMA mapping of urb->setup_packet is not necessary for xHCI host > > > controllers. The xHCI specification says that Setup Stage TRB includes > > > whole Setup Data; therefore, urb->setup_dma will not be used in the xhci > > > HCD code. > > > > > > > How about bypass map/unmap operation for xHCI control transfer directly? > > > > diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c > > index 91ab81c3fc79..0a0ab14b7638 100644 > > --- a/drivers/usb/host/xhci.c > > +++ b/drivers/usb/host/xhci.c > > @@ -1374,7 +1374,8 @@ static int xhci_map_urb_for_dma(struct usb_hcd *hcd, > > struct urb *urb, > > > > xhci = hcd_to_xhci(hcd); > > > > - if (xhci_urb_suitable_for_idt(urb)) > > + if (xhci_urb_suitable_for_idt(urb) || > > + (usb_endpoint_xfer_control(&urb->ep->desc))) > > return 0; > > Would this affect the map/unmap operations for the DATA packets in a > control transfer, along with the SETUP packet? >
Oh, you are right, Alan. We do need map/unmap operation for DATA packet in control transfer. -- Thanks, Peter Chen
