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USB Superspeed Peripherals

user_4186771
New Contributor

Hi,

I have some problem about YUV upstream and UVC GET request.

The YUV 640x480@30 preview is ok when there is no UVC CONTROL request.

But if there is a UVC GET request on the USB HIGH SPEED connection,

YUV upstream is blocked and 'CyU3PDmaChannelCommitBuffer' throws error.

Is this some kind of bandwidth limitation? or bandwidth reservation for USB CONTROL endpoint?

Any advice and suggestions will be greatly appreciated.

Environment:

  Sensor: Samsung M3085

  Device : CX3 (512KB), SDK: 1.3.3 or 1.3.4

  Preview : AmCap

Thanks in advance.

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1 Solution
Hemanth
Moderator
Moderator

Hi,

Please have a look at Section 2.3->IV->second point of FX3_SDK_TroubleShooting_Guide.pdf which is present in the below path of FX3 SDK:

C:\Program Files (x86)\Cypress\EZ-USB FX3 SDK\1.3\doc\firmware

Due to this, there is a chance that you get commit buffer failure when you perform control transfer. But video streaming should resume automatically. Can you please confirm the same?

Regards,

Hemanth

Hemanth

View solution in original post

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4 Replies
Hemanth
Moderator
Moderator

Hi,

Does the CX3 device enumerate as USB 2.0(High Speed) or 3.0(SuperSpeed)?

Regarding your statement: "But if there is a UVC GET request on the USB HIGH SPEED connection"

- Which control request is being sent when the streaming is happening?

- When you mention USB HIGH SPEED do you mean USB 2.0?

Regards,

Hemanth

Hemanth
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user_4186771
New Contributor

Hi,

The device was enumerated as USB 2.0 and the control request was UVC Extension unit request.

And the symptom is limited to YUV preview.

Thank you.

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Hemanth
Moderator
Moderator

Hi,

Please have a look at Section 2.3->IV->second point of FX3_SDK_TroubleShooting_Guide.pdf which is present in the below path of FX3 SDK:

C:\Program Files (x86)\Cypress\EZ-USB FX3 SDK\1.3\doc\firmware

Due to this, there is a chance that you get commit buffer failure when you perform control transfer. But video streaming should resume automatically. Can you please confirm the same?

Regards,

Hemanth

Hemanth

View solution in original post

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user_4186771
New Contributor

Hi,

I read the SDK TroubleShooting Guide section 2.3 and I think that the DMA suspension of bulk endpoints is the cause of this problem.

Yes, video streaming resumes after DMA blocking resolved.

Again, thank you for you quick support^^

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