[U-Boot-Users] issue for usb host bulk receiving RING from usb modem

[Wang, Steven]

Hi Guys,

 

I am porting usb host tty device driver on uboot. I just use usb
usb_bulk_msg to communicate with modem. I met the following problems.

Could you please help me resolve the following issue? Thanks in advance.

 

When I use usb usb_bulk_msg to connect one USB modem, send one AT
command (e.g. AT) to Modem, and can receive a responding message, e.g.,
OK and so on.

But When I want to use usb usb_bulk_msg to receive the RING command from
modem without sending any AT command to modem, I could not receive any
data from modem, even NAK, STALL cannot be received. Then program
timeout. But if I send ATA, the can answer the incoming call.

I do not know how to receive the data from modem, when host did not send
AT command to modem.

 

Even I use usb_submit_int_msg, I only receive NULL.

 

WHY?

 

 

Thanks & Best regards,

Steven Wang

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