How to make the host controller of IMX28 to complete the bulk transfer without short packet

[liuxing]

Hi ,

refer to the page 2216 of IMX 28 RM

The reason for the transfer completion (clearing the Active bit) determines the next state.

• CErr field decrements to zero. When this occurs the Halted bit is set to one and

Active is set to zero. This results in the hardware not advancing the queue and the

pipe halts. Software must intercede to recover.

• The device responds to the transaction with a STALL PID. When this occurs, the

Halted bit is set to one and the Active bit is set to zero. This results in the hardware

not advancing the queue and the pipe halts. Software must intercede to recover.

• The Total Bytes to Transfer field is zero after the transaction completes.

• For a zero length transaction, it was zero before the transaction was started.

When this condition occurs, the Active bit is set to zero.

• The PID code is an IN, and the number of bytes moved during the transaction is less

than the Maximum Packet Length. When this occurs, the Active bit is set to zero and

a short packet condition exists. The short-packet condition is detected during the

Advance Queue state. Refer to Split Transactions for additional rules for managing

low- and full-speed transactions.

I want to know how to make the usb driver complete the usb bulk transfer without the above condition and make the host controller to update transfer result.

[igorpadykov]

Hi liu

seems it is necessary to implement driver so number of bytes

moved during the transaction = Maximum Packet Length.

Since described behaviour occurs at errors during the transaction,

more useful approach would be to implement usb physical interface

in such way so less errors occur, please check layout rules in

i.MX6 System Development User’s Guide sect.3.11 USB recommendations

http://cache.freescale.com/files/32bit/doc/user_guide/IMX6DQ6SDLHDG.pdf

Best regards

igor

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[liuxing]

Hi,

       thanks very much!

        It seems that the section 3.11 descript the hardware layout rules of USB.I think my issue is unrelated of hardware.It looks more like IC or driver issue.