Hi, Roger Quadros <rogerq@xxxxxx> writes: >>>>>> When we set up the DWC3_DEPCMD_ENDTRANSFER command in >>>>>> dwc3_stop_active_transfer(), we can do not set DWC3_DEPCMD_CMDIOC, >>>>>> then there will no endpoint command complete interrupts I think. >>>>>> >>>>>> cmd |= DWC3_DEPCMD_CMDIOC; >>>>> >>>>> I remember some part of the databook mandating CMDIOC to be set. We >>>>> could test it out without and see if anything blows up. I would, >>>>> however, require a lengthy comment explaining that we're deviating from >>>>> databook revision x.yya, section foobar because $reasons. :-) >>>>> >>>> >>>> This is what the v3.10 databook says >>>> >>>> "When issuing an End Transfer command, software must set the CmdIOC >>>> bit (field 8) so that an Endpoint Command Complete event is generated >>>> after the transfer ends. This is necessary to synchronize the >>>> conclusion of system bus traffic before the End Transfer command is >>>> completed." >>>> >>>> with a note >>>> >>>> "If GUCTL2[Rst_actbitlater] is set, Software can poll the completion >>>> of the End Transfer command by polling the command active bit to be >>>> cleared to 0." >>>> >>>> fyi. >>>> >>>> Rst_actbitlater - "Enable clearing of the command active bit for the >>>> ENDXFER command after the command execution is completed. This bit is >>>> valid in device mode only." >>>> >>>> So I'd prefer not to clear CMDIOC for all cases. >>>> >>>> Could we some how just tackle the dwc3_gadget_exit case like I did in >>>> this patch? >>> >>> if you can send a version that doesn't iterate over all endpoints twice, >>> sure. We still need a comment somewhere, and I fear we may get >>> interrupts later in some cases. How would we deal with that? >>> >> >> how about explicitly masking that interrupt? Is it possible? >> > > Other easy option is to use wait_event_interruptible_lock_irq_timeout() > instead of wait_event_lock_irq() in dwc3_gadget_stop(). > > Is a 200ms timeout sufficient? And after the first timeout we assume all > will timeout so no point in waiting 200ms for each endpoint. We can do that. And I think some 5ms is more than enough :-) I'd be surprised if it takes anything over some 200us for the EndTransfer command to complete. -- balbi
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