[PATCH 5.18 108/141] usb: cdnsp: Fixed setting last_trb incorrectly

Greg Kroah-Hartman
2022-06-20T13:05:21Z

From: Jing Leng <jleng@ambarella.com>

commit 5c7578c39c3fffe85b7d15ca1cf8cf7ac38ec0c1 upstream.

When ZLP occurs in bulk transmission, currently cdnsp will set last_trb
for the last two TRBs, it will trigger an error "ERROR Transfer event TRB
DMA ptr not part of current TD ...".

Fixes: e913aada0683 ("usb: cdnsp: Fixed issue with ZLP")
Cc: stable <stable@kernel.org>
Acked-by: Pawel Laszczak <pawell@cadence.com>
Signed-off-by: Jing Leng <jleng@ambarella.com>
Link: https://lore.kernel.org/r/20220609021134.1606-1-3090101217@zju.edu.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/usb/cdns3/cdnsp-ring.c | 19 +++++++++++--------
1 file changed, 11 insertions(+), 8 deletions(-)

--- a/drivers/usb/cdns3/cdnsp-ring.c
+++ b/drivers/usb/cdns3/cdnsp-ring.c
@@ -1941,13 +1941,16 @@ int cdnsp_queue_bulk_tx(struct cdnsp_dev
}

if (enqd_len + trb_buff_len >= full_len) {
- if (need_zero_pkt)
- zero_len_trb = !zero_len_trb;
-
- field &= ~TRB_CHAIN;
- field |= TRB_IOC;
- more_trbs_coming = false;
- preq->td.last_trb = ring->enqueue;
+ if (need_zero_pkt && !zero_len_trb) {
+ zero_len_trb = true;
+ } else {
+ zero_len_trb = false;
+ field &= ~TRB_CHAIN;
+ field |= TRB_IOC;
+ more_trbs_coming = false;
+ need_zero_pkt = false;
+ preq->td.last_trb = ring->enqueue;
+ }
}

/* Only set interrupt on short packet for OUT endpoints. */
@@ -1962,7 +1965,7 @@ int cdnsp_queue_bulk_tx(struct cdnsp_dev
length_field = TRB_LEN(trb_buff_len) | TRB_TD_SIZE(remainder) |
TRB_INTR_TARGET(0);

- cdnsp_queue_trb(pdev, ring, more_trbs_coming | zero_len_trb,
+ cdnsp_queue_trb(pdev, ring, more_trbs_coming,
lower_32_bits(send_addr),
upper_32_bits(send_addr),
length_field,