From aaf036efe4b05b4c6e9edf0f1b6b9bb3e10f11bf Mon Sep 17 00:00:00 2001 From: Mathias Nyman Date: Thu, 20 May 2021 23:47:57 +0300 Subject: [PATCH] xhci: Fix 5.12 regression of missing xHC cache clearing command after a Stall If endpoints halts due to a stall then the dequeue pointer read from hardware may already be set ahead of the stalled TRB. After commit **FIXME** in 5.12 xhci driver won't issue a Set TR Dequeue if hardware dequeue pointer is already in the right place. Turns out the Set TR Dequeue pointer command is anyway needed as it in addition to moves the dequeue pointer clears endpoint state and cache. Signed-off-by: Mathias Nyman --- drivers/usb/host/xhci-ring.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 256d336354a0..6acd2329e08d 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -933,14 +933,18 @@ static int xhci_invalidate_cancelled_tds(struct xhci_virt_ep *ep) continue; } /* - * If ring stopped on the TD we need to cancel, then we have to + * If a ring stopped on the TD we need to cancel then we have to * move the xHC endpoint ring dequeue pointer past this TD. + * Rings halted due to STALL may show hw_deq is past the stalled + * TD, but still require a set TR Deq command to flush xHC cache. */ hw_deq = xhci_get_hw_deq(xhci, ep->vdev, ep->ep_index, td->urb->stream_id); hw_deq &= ~0xf; - if (trb_in_td(xhci, td->start_seg, td->first_trb, + if (td->cancel_status == TD_HALTED) { + cached_td = td; + } else if (trb_in_td(xhci, td->start_seg, td->first_trb, td->last_trb, hw_deq, false)) { switch (td->cancel_status) { case TD_CLEARED: /* TD is already no-op */ -- 2.25.1