omapl138 usb gadget issues

ShilpaByrichetty

Other Parts Discussed in Thread: OMAPL138We have a custom gadget driver which works perfectly fine on a dm6446 latest kernel. When the same gadget driver is run on an omap l138 logic PD board, it doesn't work as expected. When we set our receive buffer size to 4096 on the gadget, we are able to send one packet of data correctly from the host to the gadget. On the subsequent packets, we could see that the gadget receives the correct length that the host sends, but the data is not in the gadget buffer. We noticed that omapl138 uses cppi4.1 dma vs cppi dma. Is the gadget using cppi4.1 dma losing packets a known issue? Are there any specific rules that a gadget need to follow inorder to use cppi4.1 dma?

over 14 years ago

0 swami over 14 years ago

TI__Expert 7435 points

Shilpa

Can you describe your class level communication protocol over usb and a brief description of your class.

Can you confirm that you are indeed using the latest version of the kernel and the related patches (if any).

regards

swami

0 ShilpaByrichetty over 14 years ago in reply to swami

Intellectual 985 points

Swami,

We donot use predefined protocols, the class and subclass we use are vendor specific/ reserved class. Can you tell me what specific details you need regarding the protocol we are using?

We are using the kernel linux-2.6.33-rc4-psp03.20.00.13 from ti-dvsdk_omapl138-evm_4_00_00_22. Our gadget driver works fine when run in PIO mode.

Shilpa.

0 ShilpaByrichetty over 14 years ago in reply to ShilpaByrichetty

Intellectual 985 points

4010.am1808_log.txt

Swami,

Attached is the debug log in failure case.

Any help on this is appreciated.

Thanks,

Shilpa.

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omapl138 usb gadget issues