> > Can only be true for last TRB > > | if (event->status & DEPEVT_STATUS_IOC) | return 1; > > This is the problem. The whole USB request gets only one interrupt when the last TRB completes, so dwc3_gadget_ep_reclaim_trb_sg() > gets called with event->status = 0x6 which has DEPEVT_STATUS_IOC bit set. Thus dwc3_gadget_ep_reclaim_completed_trb() returns 1 > for the first TRB and the for-loop ends without having a chance to iterate through the sg list. > > > If we have a short packet, then we may fall here. Is that the case? > > No need for a short packet to make it fail. In my case below, a 16384 byte request got slipt into 4 TRBs of 4096 bytes. All TRBs were > completed normally, but the for-loop in dwc3_gadget_ep_reclaim_trb_sg() was terminated right after handling the first TRB. After that > the trb_dequeue is messed up. > > buffer_addr,size,type,ioc,isp_imi,csp,chn,lst,hwo > 0000000077849000, 4096,normal,0,0,1,1,0,0 > 000000007784a000, 4096,normal,0,0,1,1,0,0 > 000000007784b000, 4096,normal,0,0,1,1,0,0 > 000000007784c000, 4096,normal,1,0,1,0,0,0 > 000000007784d000, 512,normal,1,0,1,0,0,0 > > My first version of the patch was trying to address the issue in dwc3_gadget_ep_reclaim_completed_trb(), but then I thought it's a bad > idea to touch this function because that is also called from non scatter_gather list case, and I was not sure if returning 1 for the linear > case is correct or not. I just sent v3 of the patch. Let me know your thoughts. -Fei
