OCTVO-3P-AM335X: Ti-RTOS USB Bulk Write error lockup

Bruce Naylor

Part Number: OCTVO-3P-AM335X
Other Parts Discussed in Thread: SYSBIOS

Hi all,

I have been working on an AM335x (Octavo) based camera design running TI-RTOS (PDK 1.0.13) feeding video data on request to a Window10 PC over USB.

One thread runs the USB - wait for a bulk command, send a bulk response kinda loop. Based on the example code from TI.

One thread periodically flashes an LED to indicate the RTOS is up. and running.

printf outputs to a serial port for logging.

This can run for days without issue. If the PC is under heavy load however, a call to USBD_bulkWrite can be made to fail:

if (MAX_TRANSFER_SIZE != USBD_bulkWrite(m_hUSB, pUsbBuffer + packetOffset + transferOffset, MAX_TRANSFER_SIZE)) {
printf("[usbApp] video USB write error 0x%x 0x%x+0x%x+0x%x 0x%x\n", m_hUSB, pUsbBuffer, packetOffset, transferOffset, MAX_TRANSFER_SIZE);

}

After a write error the thread running the led hangs. Sometime I can trap an exception, but it seems random..

Any thoughts?

Bruce,.

over 4 years ago

0 Bruce Naylor over 4 years ago

Prodigy 70 points

For clarity once the led stops flashing, the USB thread no longer processes USB request, so assume the RTOS has hung up.

0 Aravind Batni over 4 years ago in reply to Bruce Naylor

TI__Expert 8885 points

Hi Bruce,

I will check with the development and get back to you.

Thanks

0 Aravind Batni over 4 years ago in reply to Aravind Batni

TI__Expert 8885 points

Hi Bruce,

Can you please share USB transaction log (using a USB analyzer) when the error is happening?

Thanks

0 Bruce Naylor over 4 years ago in reply to Aravind Batni

Prodigy 70 points

Hi Aravind, I have a log at the time of the error - don't quite understand how I can upload it to you via this forum - using a 1480A USB Protocol Analyser that seems to produce no-text .usb files. I have a screen shot, but no idea how to post it here.

0 Aravind Batni over 4 years ago in reply to Bruce Naylor

TI__Expert 8885 points

Hi Bruce,

Thanks for capturing it.

By the way, just to set the right expectations, please note that the e2e forum is meant to provide guidance for customers to narrow down if the issue is in TI deliverable.

TI would not be able to debug/help the application you developed. If you have any questions on USB LLD, USB LLD examples that is released by TI or on the USB IP, I may be able to check with respective team and get back to you.

Please let me know.

Thanks

0 Bruce Naylor over 4 years ago

Prodigy 70 points

Managed to trap the exception causing the lockup, and (I believe) the point in the USB transaction where it failed.

0 Bruce Naylor over 4 years ago in reply to Bruce Naylor

Prodigy 70 points

And the call from ti_sysbios_family_arm_a8_Cache_invL1p__I the seems to have caused the exception ...

0 Aravind Batni over 4 years ago in reply to Bruce Naylor

TI__Expert 8885 points

Hi Bruce Naylor,

Thanks for providing details. I will check internally, if we can respond to you by going through the details you provided. Note, please expect delay in response for this thread.

Thanks,

0 Bruce Naylor over 4 years ago in reply to Aravind Batni

Prodigy 70 points

Thank you Aravind - this help is much appreciated.

0 Aravind Batni over 4 years ago in reply to Bruce Naylor

TI__Expert 8885 points

Hi Bruce,

I see you had shared all the pictures via dropbox. Is it possible for you to copy and paste them to e2e thread directly?

Thanks

0 Aravind Batni over 4 years ago in reply to Aravind Batni

TI__Expert 8885 points

Hi Bruce,

Dropbox access that you shared hits below for my at TI. So, please share them in this thread only.

File Sharing Site Exception

0 Aravind Batni over 4 years ago in reply to Aravind Batni

TI__Expert 8885 points

Bi Bruce,

Hope you have resolved it at your side. Is this still outstanding from you? I have not heard from you on providing the pictures in the e2e thread. Also, please note that USB answers is not quick to get the issues answered internally.

If it is no longer an issue, please close the thread.

Thanks

0 Bruce Naylor over 4 years ago in reply to Aravind Batni

Prodigy 70 points

Hi Aravind (et all)

It appears that the USBD_bulkWrite call isn't as synchronous as it is made out to be. Waiting for the write callback to occur before calling USBD_bulkWrite again *appears* to resolve the issue I was seeing. Probably good practice even if you don't have any issues in Beta.

Thanks for the support.

Bruce.

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OCTVO-3P-AM335X: Ti-RTOS USB Bulk Write error lockup

File Sharing Site Exception