On 8/29/2016 12:33 AM, Felipe Balbi wrote: > > Hi, > > John Youn <John.Youn@xxxxxxxxxxxx> writes: >> On 8/26/2016 12:48 AM, Felipe Balbi wrote: >>> >>> Hi, >>> >>> John Youn <John.Youn@xxxxxxxxxxxx> writes: >>>> I was wondering if anyone is using the f_tcm function? Specifically >>>> for UAS in superspeed with streams? Any idea if it is being using in >>>> production for this anywhere? >>>> >>>> I've been trying to get the tcm gadget running without success. It >>>> seems I need to configure the target system via configfs and somehow >>>> interface it to this gadget. But I have not found any documentation or >>>> examples on how to get it working. Anyone have ideas or pointers? >>> >>> Sebastian has posted his scripts here several times, it's in the >>> archives :-) >> >> I found some scripts before but none of them resulted in a working >> system. Though I did manage to get something semi-working >> eventually. It would still be nice to have some documentation about >> this part especially as I have no knowledge of the target side and no >> idea what those scripts are doing. > > What do you mean by "semi-working"? How far did you get? Can you capture > tracepoints so we figure out what's wrong? > > # mkdir -p /t > # mount -t tracefs none /t > # echo 8192 > /t/buffer_size_kb > # echo 1 > /t/events/dwc3/enable > > (trigger issue) > > # cp /t/trace ~/trace.txt > > Send me trace.txt ;-) > >>> There's also a TCM python tool somewhere which helps with this. I >>> haven't used f_tcm in a long while, but Sebastian and I used it long >>> back to test streams with dwc3. >> >> Have you tried it recently? Or do you know of anyone who has? > > Sebastian is the only one I know who has used this in the past. > >>>> Just from the code it seems there will be some fundamental issues with >>>> it, such as the value of maxpacket size and some alt-interface >>>> stuff. At least when used with DWC3. >>> >>> such as? >> >> I'll see if I can write up the exact issues later. I have to go back >> to my notes to remind myself. >> >> But just in trying to get it to work, these issues make me suspect no >> one is using this driver in superspeed, or at least regularly testing >> it, let alone using it in production. > > that's probably true, but it's not enough argument to have a duplicate > implementation of it :-) Rather, we should be figuring out what's broken > and fixing it. I have a ton of other stuff to be done, but I'll add this > to my queue, no issues. > Ok thanks. I'll see if I can get back to you on the exact issues I found later this week. Regards, John -- 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
