Re: Issue with DWC3 Gadget Driver: Stall After Transmitting Only 2KB Using Scatter-Gather and TRB Chaining

[Thinh Nguyen <Thinh.Nguyen@synopsys.com>]

Hi,

On Thu, Oct 30, 2025, Li Haifeng wrote:
> Dear Greg,
> 
> Thank you for your prompt response and advice.
> 
> I just tested the issue on kernel version 6.1.17, and the problem
> persists. I will proceed to try the latest kernel release 6.17, and
> report back with the results as soon as possible.
> 
> Appreciate your guidance.
> 
> Best regards,
> Haifeng
> 

Avoid top-post if you can.

As Greg noted, please try the recent kernel release. For now, let's take
a look at what you already have.

This is from your previous email:

	- The device side only transmits the first 2KB of data.
	- The host acknowledges this partial transfer (ACK received).
	- After the ACK, the device does not respond or continue the
	transfer—no further data is sent, and the endpoint appears to stall
	without triggering any completion callback or error.

You mentioned host ACK'ed IN data, so I assume you run in SuperSpeed and
have a usb traffic analyzer and able to see these packets. Did you see
the host requesting for the next set of data? My suspiction is it did
not. There's no mention of NRDY or flow control here. If the device did
not prepare enough TRBs, you'd see flow control.

Check your host.

BR,
Thinh