Patch modifies the TD_SIZE in TRB before ZLP TRB.
The TD_SIZE in TRB before ZLP TRB must be set to 1 to force
processing ZLP TRB by controller.
cc: <stable@xxxxxxxxxxxxxxx>
Fixes: 3d82904559f4 ("usb: cdnsp: cdns3 Add main part of Cadence USBSSP DRD Driver")
Signed-off-by: Pawel Laszczak <pawell@xxxxxxxxxxx>
---
Changelog:
v2:
- returned value for last TRB must be 0
drivers/usb/cdns3/cdnsp-ring.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/cdns3/cdnsp-ring.c b/drivers/usb/cdns3/cdnsp-ring.c
index 04dfcaa08dc4..aa79bce89d8a 100644
--- a/drivers/usb/cdns3/cdnsp-ring.c
+++ b/drivers/usb/cdns3/cdnsp-ring.c
@@ -1769,8 +1769,13 @@ static u32 cdnsp_td_remainder(struct cdnsp_device *pdev,
/* One TRB with a zero-length data packet. */
if (!more_trbs_coming || (transferred == 0 && trb_buff_len == 0) ||
- trb_buff_len == td_total_len)
+ trb_buff_len == td_total_len) {
+ /* Before ZLP driver needs set TD_SIZE=1. */
+ if (more_trbs_coming)
+ return 1;
+
return 0;
+ }
maxp = usb_endpoint_maxp(preq->pep->endpoint.desc);
total_packet_count = DIV_ROUND_UP(td_total_len, maxp);
--
2.25.1
