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USB superspeed peripherals Forum Discussions

StFa_289656
Level 2
Level 2

I made a composite USB device: UVC + HID.

framework 1.3.4

The uvc is based on AN75779.

the USB communication stop working after few seconds using USB 2.0 (USB 3.0 is ok).

I faced a similar problem with UVC when I asked extended properties very often.

Has Anyone a similar probelm?

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1 Solution

Hello,

- Please confirm that you made appropriate changes in the HIGH speed and full speed descriptors for adding  HID and extension unit.

- Are you getting any debug prints when the streaming is stopped. It seems that  Host is slow enough to issue IN tokens ( can be  the reason for overflow.

Please refer this KBAInvalid Sequence Error in Multi-Channel Commit Buffer - KBA218830  and try the changes recommended.

If this doesn't help, please probe the USB lines and share the traces. You can use Wireshark for that.

Regards,

Rashi

Regards,
Rashi

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5 Replies
Rashi_Vatsa
Moderator
Moderator
Moderator
5 likes given 500 solutions authored 1000 replies posted

Hello,

USB 2.0 practically supports the bandwidth of 20-25 MBps. Please confirm the video stream bandwidth is <= 25MBps

What are the errors you are getting while streaming in USB 2.0

I faced a similar problem with UVC when I asked extended properties very often.

>> Does this happen in USB 2.0 or USB 3.0? What are the errors?

Regards,

Rashi

Regards,
Rashi
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Hello,

the video stream is about 25Mbps.

without communication with the HID or the extended properties the video works fine.

the error is alwasys the same: the USB staks stop to transmit data.

I have a dedicated task used to perform some operation and this task is still working.

removing the usb cable and attach it again resolve the problem (this is not acceptable).

I think there is something in the FX3 libs that don't take care to an overflow situation.

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Hello,

- Please confirm that you made appropriate changes in the HIGH speed and full speed descriptors for adding  HID and extension unit.

- Are you getting any debug prints when the streaming is stopped. It seems that  Host is slow enough to issue IN tokens ( can be  the reason for overflow.

Please refer this KBAInvalid Sequence Error in Multi-Channel Commit Buffer - KBA218830  and try the changes recommended.

If this doesn't help, please probe the USB lines and share the traces. You can use Wireshark for that.

Regards,

Rashi

Regards,
Rashi
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- Please confirm that you made appropriate changes in the HIGH speed and full speed descriptors for adding  HID and extension unit.

Yes I made a combi peripheral. I dont use and don't initialize the Full speed descriptor.

- Are you getting any debug prints when the streaming is stopped. It seems that  Host is slow enough to issue IN tokens ( can be  the reason for overflow.

I don't have the UART available, so no debug print

I'm going to test the KBA you suggest me, I'll keep you informed

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Hello,

Can you debug on your side that where is the firmware failing? Please check with that CyU3PDmaMultiChannelCommitBuffer API is passing or failing.

If it is passing probe the USB lines and share the traces.

Please let me know the results for changes in KBA.

Regards,

Rashi

Regards,
Rashi
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