Hi,
I have been trying to add MTP support in iMX6ULL. Linux kernel version is 4.1.15.
I found open source uMTP responder online.
GitHub - viveris/uMTP-Responder: Ligthweight Media Transfer Protocol (MTP) responder daemon for GNU/...
It is a user space MTP daemon written in "C". It runs through gadgetfs. You can find more information and source code in above link.
I have followed below steps to run it on iMX6ULL EVK.
modprobe gadgetfs
mkdir -p /dev/gadget
mount -t gadgetfs none /dev/gadget
When I run the mtp daemon, EVK got hanged. I could no longer operate EVK on serial console. The host PC which is connected to EVK through OTG can not read USB descriptor information. USB device could not be enumerated in host PC.
Below are the debug logs.
root@imx6ull14x14evk:~/uMTP-Responder# ./umtprd
[Info] uMTP Responder
[Info] Version: v0.8.1 compiled the Jun 19 2018@15:21:51
[Info] (c) 2018 Viveris Technologies
[ 23.891322] gadgetfs: bound to 2184000.usb driver
[Debug] init_mtp_responder
[Debug] init_mtp_responder : Ok !
[Info] Add storage home folder - Root Path: /home
[Debug] mtp_add_storage : /home
[Debug] mtp_add_storage : Storage 00000001 mapped to /home (home folder)
[Info] USB Device path : /dev/gadget/2184000.usb
[Info] USB In End point path : /dev/gadget/ep1in
[Info] USB Out End point path : /dev/gadget/ep2out
[Info] USB Event End point path : /dev/gadget/ep3in
[Info] USB Max packet size : 0x200 bytes
[Info] Manufacturer string : Viveris Technologies
[Info] Product string : The Viveris Product !
[Info] Serial string : 01234567
[Info] Interface string : MTP
[Info] USB Vendor ID : 0x1D6B
[Info] USB Product ID : 0x0100
[Info] USB class ID : 0x06
[Info] USB subclass ID : 0x01
[Info] USB Protocol ID : 0x01
[Info] USB Device version : 0x3008
[Debug] fill_config_descriptor: (Total Len : 9 + 30 = 39)
[Debug]
09 02 27 00 01 01 05 80 01
[Debug] fill_if_descriptor:
[Debug]
09 04 00 00 03 06 01 01 06
[Debug] fill_ep_descriptor:
[Debug]
07 05 81 02 00 02 00
[Debug] fill_ep_descriptor:
[Debug]
07 05 02 02 00 02 00
[Debug] fill_ep_descriptor:
[Debug]
07 05 83 03 1C 00 06
[Debug] fill_config_descriptor: (Total Len : 9 + 30 = 39)
[Debug]
09 02 27 00 01 01 04 80 01
[Debug] fill_if_descriptor:
[Debug]
09 04 00 00 03 06 01 01 06
[Debug] fill_ep_descriptor:
[Debug]
07 05 81 02 00 02 00
[Debug] fill_ep_descriptor:
[Debug]
07 05 02 02 00 02 00
[Debug] fill_ep_descriptor:
[Debug]
07 05 83 03 1C 00 06
[Debug] fill_dev_descriptor:
[Debug]
12 01 00 00 06 01 01 00 6B 1D 00 01 08 30 01 02
03 01
[Debug] init_usb_mtp_gadget :
[Debug]
00 00 00 00 09 02 27 00 01 01 05 80 01 09 04 00
00 03 06 01 01 06 07 05 81 02 00 02 00 07 05 02
02 00 02 00 07 05 83 03 1C 00 06 09 02 27 00 01
01 04 80 01 09 04 00 00 03 06 01 01 06 07 05 81
02 00 02 00 07 05 02 02 00 02 00 07 05 83 03 1C
00 06 12 01 00 00 06 01 01 00 6B 1D 00 01 08 30
01 02 03 01
[Info] init_usb_mtp_gadget : USB config done
[Debug] handle_ep0 : Entering...
[Debug] 1 event(s)
[Debug] EP0 DISCONNECT
[Debug] 2 event(s)
I tried debugging chipidea UDC and gadgetfs drivers but could not find the root cause.
I have successfully run uMTP on Beagle bone black. Which uses musb-hdrc.
If anyone have any idea about what could be wrong here, please answer asap.
