On Wed, 27 Nov 2019 at 16:56, Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx> wrote: > > On 27.11.2019 17.30, Ard Biesheuvel wrote: > > When using a USB webcam on a ThunderX2 workstation, the kernel log > > gets flooded with messages like > > > > xhci_hcd 0000:00:0f.0: > > WARN Successful completion on short TX for slot 7 ep 2: needs XHCI_TRUST_TX_LENGTH quirk? > > > > Enabling the quirk manually makes the issue go away, so let's enable > > it unconditionally for this hardware. > > > > This issue starts to be common for many vendors, many report successful > completions after a initial short transfer in a TD > > Does the patch below help in your case? It worked for a Renesas controller > with similar issues. It's a more generic solution. > > diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c > index 9ebaa8e132a9..d23f7408c81f 100644 > --- a/drivers/usb/host/xhci-ring.c > +++ b/drivers/usb/host/xhci-ring.c > @@ -2381,7 +2381,8 @@ static int handle_tx_event(struct xhci_hcd *xhci, > case COMP_SUCCESS: > if (EVENT_TRB_LEN(le32_to_cpu(event->transfer_len)) == 0) > break; > - if (xhci->quirks & XHCI_TRUST_TX_LENGTH) > + if (xhci->quirks & XHCI_TRUST_TX_LENGTH || > + ep_ring->last_td_was_short) > trb_comp_code = COMP_SHORT_PACKET; > else > xhci_warn_ratelimited(xhci, Yes, that works too. If you roll that into a patch Tested-by: Ard Biesheuvel <ardb@xxxxxxxxxx> and please consider cc'ing stable as well.
