AM335x USB Peripheral Mode sending a STALL packet

Daisuke Maeda

Guru 19835 points

Our customer sees that a STALL packet is sent by using the USB Protocol Analyzer. It sometimes shows up at the second IN Data phase in a GET_DESCRIPTOR(CONFIGURATION) transaction. After a STALL packet is sent, the SENTSTALL bit is set and an interrupt is generated in the case of most, but they are not done in rare cases.

Can you guess what the cause of this issue is? Any advice or information you could provide would be greatly appreciated.

Best regards,

Daisuke

over 9 years ago

0 Biser Gatchev-XID over 9 years ago

TI__Guru**** 393215 points

Could you please provide more details on the hardware setup, software used etc.?

0 Daisuke Maeda over 9 years ago in reply to Biser Gatchev-XID

Guru 19835 points

Hi Biser,

Thank you for your reply.

The customer hardly doubts their software because the software seems to not set the SENDSTALL bit while it runs.

When the controller has sent the STALL packet, is there the case that the SENTSTALL bit is not set?

After the SENTSTALL bit is set, is it kept set until the software clears it?

I am going to obtain more details from the customer.

Best regards,

Daisuke

0 Bin Liu over 9 years ago in reply to Daisuke Maeda

TI__Guru*** 125176 points

Daisuke,

Daisuke Maeda said:
The customer hardly doubts their software because the software seems to not set the SENDSTALL bit while it runs.

This is most likely caused by the software (the MUSB controller peripheral-mode driver) which does not handle the control transfers properly, or the host driver does not send proper control transfers.

Is this on Linux? If so, what is the AMSDK version?

Daisuke Maeda said:
When the controller has sent the STALL packet, is there the case that the SENTSTALL bit is not set?

No, CSR0L[SENTSTALL] will be set after the STALL packet is sent.

Daisuke Maeda said:
After the SENTSTALL bit is set, is it kept set until the software clears it?

the software has to clear it.

0 Daisuke Maeda over 9 years ago in reply to Bin Liu

Guru 19835 points

Hi Bin,

Thank you for your reply.

Our customer uses the StarterWare-based software. It is debugged on CCS.

Best regards,

Daisuke

0 Bin Liu over 9 years ago in reply to Daisuke Maeda

TI__Guru*** 125176 points

Daisuke,

Sorry I don't have expertise on StarterWare and this forum only supports Linux.

StarterWare support forum is e2e.ti.com/.../790.

0 Daisuke Maeda over 8 years ago in reply to Bin Liu

Guru 19835 points

Hi Bin,

Thank you for your reply.

I ask about the AM335x device on this Sitara Forum. Please continue to give us your support.

The DATAEND bit is set by a software to indicate that the data phase is complete and is cleared automatically. When is this bit cleared?

Our customer saw that the DATAEND bit has been set after the STALL packet was sent.

Best regards,

Daisuke

0 Bin Liu over 8 years ago in reply to Daisuke Maeda

TI__Guru*** 125176 points

Daisuke,

The SATAEND bit is self-clearing. The MUSB manual does not describe when exactly the bit gets cleared.

0 Daisuke Maeda over 8 years ago in reply to Bin Liu

Guru 19835 points

Hi Bin,

Thank you for your reply. Sorry for my late reply.

Best regards,

Daisuke

0 Bin Liu over 8 years ago in reply to Daisuke Maeda

TI__Guru*** 125176 points

Daisuke, no worries.

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AM335x USB Peripheral Mode sending a STALL packet