Thinh Nguyen wrote: > Hi, > > Wesley Cheng wrote: >> From: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx> >> >> If the request being dequeued is currently active, then the current >> logic is to issue a stop transfer command, and allow the command >> completion to cleanup the cancelled list. The DWC3 controller will >> run into an end transfer command timeout if there is an ongoing EP0 >> transaction. If this is the case, wait for the EP0 completion event >> before proceeding to retry the endxfer command again. > > Can you fix the commit message as follow: > > If a Setup packet is received but yet to DMA out, the controller will > not process the End Transfer command of any endpoint. Polling of its > DEPCMD.CmdAct may block setting up TRB for Setup packet, causing a > command timeout. > > This may occur if the driver doesn’t service the completion interrupt of > the control status stage yet due to system latency, then it won’t > prepare TRB and start the transfer for the next Setup Stage. To the host > side, the control transfer had completed, and the host can send a new > Setup packet at this point. > > In the meanwhile, if the driver receives an async call to dequeue a > request (triggering End Transfer) to any endpoint, then the driver will > service that End transfer first, blocking the control status stage > completion handler. Since no TRB is available for the Setup stage, the > Setup packet can’t be DMA’ed out and the End Transfer gets hung. > > The driver must not block setting up of the Setup stage. So track and > only issue the End Transfer command only when there’s Setup TRB prepared > so that the controller can DMA out the Setup packet. Delay the End > transfer command until there's no Setup TRB available. This is typo: Delay the End transfer command *if* there's no Setup TRB available. > applicable to all DWC_usb3x IPs. >
