AM5718: USB device Enumeration Problems

Gibbs Shih

Part Number: AM5718

Hi, TI Expert.

Our customer use AM5718 as "USB device", and connect to x86 platform "USB Host".

Block diagram as below.

We found USB device (AM5718) even enumeration success, but it seems always try to re-connect & appear incompatible ico , status as below.

So we try to capture USB packet for debugging,

* Failed (left), Success (right)

As far as I know, we found something different, it includes :

1. Device enumeration success for failed one.

2. Device already pass Rx.Detect -> Polling -> U0 status

3, Not sure the reason, Why state machine always swap between U0 and Recovery mode.

As far as I know, "Polling state" will make sure USB physical link quality is fine, Isn't it?

My question is :

1. What's the situation let USB always swap between U0 & Recovery state?

2. U0 seems face some error, so I think it try to re-established connection.

Need debug suggestion.

Thanks

Gibbs

over 2 years ago

0 Josue Zamitiz-Ayala over 2 years ago

TI__Mastermind 37886 points

Hello Gibbs,

I will look into this this week and get back to you by the end of the week. Can you confirm that customer is using Linux kernel 4.9? This belongs to a very old SDK release and is very hard for us to support.

-Josue

0 Gibbs Shih over 2 years ago in reply to Josue Zamitiz-Ayala

TI__Expert 6005 points

Thanks, Josue

I will ask customer provide related information

Gibbs

0 louis.lin over 2 years ago in reply to Josue Zamitiz-Ayala

Prodigy 10 points

Hi Josue,

Our customer is using Linux kernel 4.9.59

Louis

0 Josue Zamitiz-Ayala over 2 years ago in reply to louis.lin

TI__Mastermind 37886 points

Louis,

Do you have any logs from the processor? Can you ask the customer for error logs?

-Josue

0 Gibbs Shih over 2 years ago in reply to Josue Zamitiz-Ayala

TI__Expert 6005 points

Hi, Josue

I try to help Louis identify issue at the same time.

Before Louis release kernel error log to us, I have some question need clarification too.

I think (guess) AM5718 (device mode) try to swap U0 to U3 state , and face some error.

It should be LPM problem.

(Capture by USB Sniffer)

Success work : AM5718 -> USB HUB -> USB HOST (x86)

Failed work : AM5718 -> USB HOST (x86)

I guess USB Hub have better LPM support

I think periodic time out is ok, because HOST need to query device few time to make sure device is no-active.

If request timeout, than HOST swap to U3.

So, how about that LPM always keep active state?

How to disable LPM on AM5718 USB device mode?

If idea is wrong, pls correct me!

Many Thanks

Gibbs

0 Josue Zamitiz-Ayala over 2 years ago in reply to Gibbs Shih

TI__Mastermind 37886 points

Gibbs,

Please see the https://git.ti.com/cgit/ti-linux-kernel/ti-linux-kernel/tree/Documentation/devicetree/bindings/usb/dwc3.txt

I believe if you can add certain entries in the device tree to disable any additional power states and force the driver to stay on.

See

dis-u1-entry-quirk.

dis-u2-entry-quirk.

Best,

Josue

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AM5718: USB device Enumeration Problems