TX1 Tegra XUDC controller error

Robotics & Edge Computing Jetson & Embedded Systems Jetson TX1
1

In my ongoing effort to get bulk mode working for the USB webcam gadget, I’ve stumbled across another clue I’m trying to track down. This appears in the logs, coming from drivers/usb/gadget/udc/tegra_xudc.c line 3030. TRB type 0x25 isn’t defined, but after some searching appears to be TRB_TYPE_HOST_CONTROLLER_EVENT.

Anyone have any idea what the host controller is trying to report back to the kernel? Or a way to debug this further?

[Fri Aug 24 11:26:02 2018] [ 90.266672] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:02 2018] [ 90.623606] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:02 2018] [ 90.890673] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:03 2018] [ 91.154899] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:03 2018] [ 91.420229] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:03 2018] [ 91.684271] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:03 2018] [ 91.948204] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:04 2018] [ 92.212518] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:04 2018] [ 92.477156] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:04 2018] [ 92.741304] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:04 2018] [ 93.004615] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:05 2018] [ 93.268101] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:05 2018] [ 93.531380] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:05 2018] [ 93.795775] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:06 2018] [ 94.059072] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:06 2018] [ 94.323608] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:06 2018] [ 94.587867] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:06 2018] [ 94.854172] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:07 2018] [ 95.118144] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:07 2018] [ 95.382324] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:07 2018] [ 95.646345] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:07 2018] [ 95.910575] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:08 2018] [ 96.173761] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:08 2018] [ 96.440522] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:08 2018] [ 96.704072] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:08 2018] [ 96.967636] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:09 2018] [ 97.232693] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:09 2018] [ 97.496455] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:09 2018] [ 97.759320] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:09 2018] [ 98.022459] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:10 2018] [ 98.287368] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:10 2018] [ 98.550128] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:10 2018] [ 98.813020] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:11 2018] [ 99.078185] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:11 2018] [ 99.340909] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:11 2018] [ 99.604421] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:11 2018] [ 99.867339] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25
[Fri Aug 24 11:26:12 2018] [ 100.130476] tegra-xudc-new 700d0000.xudc: Unrecognized TRB type = 0x25

2

Are you trying to make the OTG port in device mode appear to be an isochronous mode camera? If so, then this port does not support isochronous. I suspect this is what the TRB type is for, but I have not attempted to verify. If this is the case, then you’ll have to switch to something like bulk mode instead of isochronous.

3

Not isochronous, no. The kernel is carrying a set of changes to the UVC gadget driver to make it request bulk endpoints instead of ISOCH. The above is what happens with the changes for bulk mode.

4

In that case I don’t know what is going on. I’m not sure what the TRB 0x25 represents.

5

37 (0x25) appears to be a host controller event. See the matching definition here: edk2/DebugCommunicationLibUsb3Internal.h at master · tianocore/edk2 · GitHub

Also, section 6.4.6 of this document: http://composter.com.ua/documents/xHCI_Specification_for_USB.pdf

6

Hi,
We don’t have much experience in USB webcam gadget. Wish other users can share experience.

If the issue can be reproduced with Logitech c930 or e-con See3CAM_CU135 usb cams, please share us steps so that we can reproduce the issue and do further check.

7

Hello DaneLLL,

Is there any documentation that can be shared on the Tegra XUDC controller? I’d like to add a bit of diagnostics to drivers/usb/gadget/udc/tegra_xudc.c for the TRB_TYPE_HOST_CONTROLLER_EVENT case generated by the controller.

8

Hi,
The controller follows USB standard. Please refer to section 6.4.2.6 in
https://www.google.com.tw/search?q=xhci+specification&oq=xhci+specification&aqs=chrome..69i57j0l5.7750j0j8&sourceid=chrome&ie=UTF-8

It should give information about dump_trb().