AnsweredAssumed Answered

iMX6q - Problem with Low-speed device

Question asked by Łukasz Majewski on Oct 18, 2017
Latest reply on Oct 26, 2017 by Łukasz Majewski

Dear All,

 

I'm using iMX6q for my application. It uses the touchscreen IC connected via USB port (Host port 1). The touchscreen operates with low-speed.

 

Board: Wandboard rev1b

SW: Mainline Linux 4.13

 

Problem:

 

I do observe that the USB transfers are truncated - for example

"Get Configuration Descriptor", which length is 34 only gets 16B from the device.

I do get the "Invalid PID sequence" error and despite the DATA1 Packet received by host - the EHCI controller is not sending ACK.

 

 

 

The problem is not observed when I plug the touchscreen device via USB 2.0 HUB.

Also, the problem is not present on different EHCI implementations - namely Intel or Synopsis.

 

Have anybody had similar problem?

 

Thanks in advance,

Łukasz

Outcomes