[PATCH] usb: xhci: fix DMA address corruption in abort_td

[ANANDHAKRISHNAN S]

When aborting a Transfer Descriptor (TD), the xHCI driver updates the
device dequeue pointer by converting the virtual enqueue TRB pointer
into a DMA address.

Previously, the code OR-ed the ring's Dequeue Cycle State (DCS) bit into
the virtual TRB pointer before passing it to xhci_trb_virt_to_dma().
This produced an unaligned virtual address (e.g. ending in 0x...1).

Inside xhci_trb_virt_to_dma(), the offset calculation:

segment_offset = trb - seg->trbs;

operated on this unaligned pointer, resulting in an incorrect TRB index.
In wraparound cases, this caused the bounds check to fail and the
function to return 0.

As a result, a SET_DEQ_PTR command was issued with a DMA address of 0x0,
leading to controller hangs and transfer timeouts, most commonly when
aborting TDs near the end of a ring segment (e.g. index 63).

Fix this by translating the aligned virtual TRB pointer to a DMA address
first, and only then applying the DCS bit to the resulting physical
address.

Signed-off-by: ANANDHAKRISHNAN S <anandhakrishnan.s at dicortech.com>
---
 drivers/usb/host/xhci-ring.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 34eb4536f0e..9e0ff71710a 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -582,9 +582,11 @@ static void abort_td(struct usb_device *udev, int ep_index)
 		TRB_TO_SLOT_ID(le32_to_cpu(event->event_cmd.flags)) != udev->slot_id ||
 		(comp != COMP_SUCCESS && comp != COMP_CTX_STATE));
 	xhci_acknowledge_event(ctrl);
-
-	addr = xhci_trb_virt_to_dma(ring->enq_seg,
-		(void *)((uintptr_t)ring->enqueue | ring->cycle_state));
+	addr = xhci_trb_virt_to_dma(ring->enq_seg, ring->enqueue);
+	if (ring->cycle_state)
+		addr |= 0x1ULL;
+	else
+		addr &= ~0x1ULL;
 	xhci_queue_command(ctrl, addr, udev->slot_id, ep_index, TRB_SET_DEQ);
 	event = xhci_wait_for_event(ctrl, TRB_COMPLETION);
 	if (!event)
-- 
2.25.1