Say we have three requests prepared to the HW (reqA,
reqB, and reqC). All of them are composed of
SG-lists with several entries and they all requests
interrupt only on last TRBs of the SG-list.
When we get interrupt for reqA, it could be that
reqB is already half-way transferred and some of its
TRBs will have HWO already cleared.
It's okay to free up TRBs without HWO bit set, but
we need to guarantee we don't giveback a request
that's half-way transferred as that will confuse
gadget drivers.
Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>
---
drivers/usb/dwc3/gadget.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index bca4150e3cf5..bf8a85e80fb9 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -2106,6 +2106,9 @@ static int dwc3_cleanup_done_reqs(struct dwc3 *dwc, struct dwc3_ep *dep,
for_each_sg(sg, s, pending, i) {
trb = &dep->trb_pool[dep->trb_dequeue];
+ if (trb->ctrl & DWC3_TRB_CTRL_HWO)
+ break;
+
req->sg = sg_next(s);
req->num_pending_sgs--;
--
2.10.1
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