Hi,
>
> Gerd, do you know the purpose of the 'short_not_ok' parameter to
> usb_packet_setup()?
Well, some usb host controllers have a flag in the transfer control
blocks to indicate the host controller should stop processing requests
in case of a short transfer.
The usb core uses the flag to just to that (i.e. halt the endpoint on
short transfers). It is also checked when usb-host pipelines requests
(requests queued after a short-not-ok packet can't be pipelined because
we don't know yet whenever we should continue processing the endpoint or
not).
xhci has no such flag so the flag is never set.
> The simple patch below fixes the reported problem,
> but I don't know if it could cause some other problems for XHCI.
> hcd-ehci, hcd-ohci, hcd-uhci all set the parameter conditionally,
> but hcd-xhci never sets it. I don't understand the purpose of the
> parameter myself.
>
> diff --git a/hw/usb/hcd-xhci.c b/hw/usb/hcd-xhci.c
> index b330e36fe6..9fb96fdd66 100644
> --- a/hw/usb/hcd-xhci.c
> +++ b/hw/usb/hcd-xhci.c
> @@ -1614,7 +1614,7 @@ static int xhci_setup_packet(XHCITransfer *xfer)
> xhci_xfer_create_sgl(xfer, dir == USB_TOKEN_IN); /* Also sets int_req */
> usb_packet_setup(&xfer->packet, dir, ep, xfer->streamid,
> - xfer->trbs[0].addr, false, xfer->int_req);
> + xfer->trbs[0].addr, dir == USB_TOKEN_IN, xfer->int_req);
I suspect this might lead to queues being halted even though they should
not.
Why does 7ad3d51ebb8a522ffcad391c4bef281245739dde look at short-not-ok?
Because the patch changes dev-storage to terminate the transfer if a
short packet is received, so I figured 'short-not-ok' should affect
that behavior.
I guess instead I could add another flag that only hcd-dwc2 sets. Does
that sound OK to you?
Thanks,
Paul
take care,
Gerd