TUSB2046B: Linux Ethernet Gadget stopped working

Lukas Sturm

Part Number: TUSB2046B

I am currently facing a problem using the TUSB2046 USB hub in combination with my SAMA5 controller. First, controller's USB Device High Speed Data interface is connected to DM_1/DP_1, and second controller's serial debug console (via Serial2USB) is connected to DM_2/DP_2. Finally, DM_0/DP_0 is connected to an USB jack so that you need only one cable.

While using kernel v4.19, die USB Ethernet Gadget via the USB hub worked perfectly, but with the migration to kernel v5.4 it stopped working. Are there any known issues regarding this setup?

Any help is appreciated!

over 4 years ago

0 JMMN over 4 years ago

TI__Guru 60870 points

Hi Lukas,

No known issues, but the TUSB2046B is a full speed hub and all traffic through it will be at full speed (12 Mbps), not high speed (480 Mbps).

Is the hub detected? Can you send a usbmon log of the failure?

Regards,

JMMN

0 JMMN over 4 years ago in reply to JMMN

TI__Guru 60870 points

Hi Lukas,

Any update here?

Regards,

JMMN

0 Lukas Sturm over 4 years ago in reply to JMMN

Prodigy 10 points

Hi JMMN,

sorry, your first reply went somehow into my spam folder. Right now I had not had the time to investigate this topic further, I will share my results (hopefully) in the upcoming week.

Thanks!

0 Lukas Sturm over 4 years ago in reply to Lukas Sturm

Prodigy 10 points

Hi JMMN,

we have finally solved this issue, in the end, it was indeed the combination of a full-speed hub and a controller which wants to use high-speed all the time. The solution was nothing hub- but kernel-related.

Thanks anyway!

Interface

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TUSB2046B: Linux Ethernet Gadget stopped working