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>
---
drivers/usb/cdns3/cdnsp-ring.c | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)
diff --git a/drivers/usb/cdns3/cdnsp-ring.c b/drivers/usb/cdns3/cdnsp-ring.c
index 794e413800ae..4809d0e894bb 100644
--- a/drivers/usb/cdns3/cdnsp-ring.c
+++ b/drivers/usb/cdns3/cdnsp-ring.c
@@ -1765,18 +1765,19 @@ static u32 cdnsp_td_remainder(struct cdnsp_device *pdev,
struct cdnsp_request *preq,
bool more_trbs_coming)
{
- u32 maxp, total_packet_count;
-
- /* One TRB with a zero-length data packet. */
- if (!more_trbs_coming || (transferred == 0 && trb_buff_len == 0) ||
- trb_buff_len == td_total_len)
- return 0;
+ u32 maxp, total_packet_count, remainder;
maxp = usb_endpoint_maxp(preq->pep->endpoint.desc);
total_packet_count = DIV_ROUND_UP(td_total_len, maxp);
/* Queuing functions don't count the current TRB into transferred. */
- return (total_packet_count - ((transferred + trb_buff_len) / maxp));
+ remainder = (total_packet_count - ((transferred + trb_buff_len) / maxp));
+
+ /* Before ZLP driver needs set TD_SIZE=1. */
+ if (!remainder && more_trbs_coming)
+ remainder = 1;
+
+ return remainder;
}
static int cdnsp_align_td(struct cdnsp_device *pdev,
--
2.25.1
