[PATCH v5 7/8] usb: dwc3: Check for IOC/LST bit in both event->status and TRB->ctrl fields

Anurag Kumar Vulisha
2018-09-15T14:30:54Z

The present code in dwc3_gadget_ep_reclaim_completed_trb() will check
for IOC/LST bit in the event->status and returns if IOC/LST bit is
set. This logic doesn't work if multiple TRBs are queued per
request and the IOC/LST bit is set on the last TRB of that request.
Consider an example where a queued request has multiple queued TRBs
and IOC/LST bit is set only for the last TRB. In this case, the Core
generates XferComplete/XferInProgress events only for the last TRB
(since IOC/LST are set only for the last TRB). As per the logic in
dwc3_gadget_ep_reclaim_completed_trb() event->status is checked for
IOC/LST bit and returns on the first TRB. This makes the remaining
TRBs left unhandled.
To aviod this, changed the code to check for IOC/LST bits in both
event->status & TRB->ctrl. This patch does the same.

Signed-off-by: Anurag Kumar Vulisha <anurag.kumar.vulisha@xilinx.com>
Reviewed-by: Thinh Nguyen <thinhn@synopsys.com>
---
Changes in v5:
1. None

Changes in v4:
1. None

Changes in v3:
1. None

Changes in v2:
1. None
---
drivers/usb/dwc3/gadget.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 1cb7df9..872c956 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -2299,7 +2299,12 @@ static int dwc3_gadget_ep_reclaim_completed_trb(struct dwc3_ep *dep,
if (event->status & DEPEVT_STATUS_SHORT && !chain)
return 1;

- if (event->status & (DEPEVT_STATUS_IOC | DEPEVT_STATUS_LST))
+ if ((event->status & DEPEVT_STATUS_IOC) &&
+ (trb->ctrl & DWC3_TRB_CTRL_IOC))
+ return 1;
+
+ if ((event->status & DEPEVT_STATUS_LST) &&
+ (trb->ctrl & DWC3_TRB_CTRL_LST))
return 1;

return 0;
--
2.1.1