On 09/03/18 11:26, Roger Quadros wrote: > On 09/03/18 11:23, Felipe Balbi wrote: >> >> Hi, >> >> Roger Quadros <rogerq@xxxxxx> writes: >> >> <snip> >> >>>>> 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. -- cheers, -roger Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
