Hi, Baolin Wang <baolin.wang@xxxxxxxxxx> writes: >>> Baolin Wang <baolin.wang@xxxxxxxxxx> writes: >>>>>>> I'm thinking this is a bug in configfs interface of Gadget API, not >>>>>>> dwc3. The only reason for this to happen would be if we get to >>>>>>> ->udc_stop() with endpoints still enabled. >>>>>>> >>>>>>> Can you check if that's the case? i.e. can you check if any endpoints >>>>>>> are still enabled when we get here? >>>>>> >>>>>> No, it is not any endpoints are still enabled. Like I said in commit >>>>>> message, we will start end transfer command when disable the endpoint, >>>>>> if the end transfer command complete event comes after we have freed >>>>>> the gadget irq, it will trigger the interrupt line all the time to >>>>>> crash the system. >>>>> >>>>> I see what the problem is. Databook tells us we *must* set CMDIOC when >>>>> issuing EndTransfer command and we should always wait for Command >>>>> Complete IRQ. However, we took a shortcut and just delayed for 100us >>>>> after issuing End Transfer. >>>> >>>> Yes, but 100us delay is not enough in some scenarios, like changing >>>> function with configfs frequently, we will met problems. >>> >>> heh, 100us *is* enough. However we still get an IRQ because we requested >>> for it. If you want to fix this, then you need to find a way to get rid >>> of that 100us udelay() and add a proper wait_for_completion() to delay >>> execution until command complete IRQ fires up. >> >> I haven't tested this yet, but it shows the idea (I think we might still >> have a race with ep_queue if we're still waiting for End Transfer, but > > Yes, maybe we need check DWC3_EP_END_TRANSFER_PENDING flag when > queuing one request. Yeah, I'll add that check later. I still need to make sure we would still try to kick any transfers that might have been queued while waiting for End Transfer Command Complete IRQ. >> that's easy to sort out by checking for DWC3_EP_END_TRANSFER_PENDING >> before calling kick_transfer). Could you have a look and, perhaps, run a >> test? > > Sure. I will test it and send out the result tomorrow. Thank you -- balbi
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