soc can't sent command to pass eye diagram test

Hi,

Which SOC are you using and is the SOC on the same computer which runs USBxHSETT tool? If the SOC is on the same computer, then you should able to use the USBxHSETT tool to force the hub to generate a test packet on its downstream port using USB Test_Packet command for that specific port.

Thanks

David

we use SA8155. it is a chip for auto. this picture show how we use 8020.

8155 can send below command:

kernel/msm-5.4/drivers/usb/misc/ehset.c
13 #define TEST_SE0_NAK_PID 0x0101
14 #define TEST_J_PID 0x0102
15 #define TEST_K_PID 0x0103
16 #define TEST_PACKET_PID 0x0104
17 #define TEST_HS_HOST_PORT_SUSPEND_RESUME 0x0106
18 #define TEST_SINGLE_STEP_GET_DEV_DESC 0x0107
19 #define TEST_SINGLE_STEP_SET_FEATURE 0x0108

We tried to use 8155 to send  16 #define TEST_PACKET_PID 0x0104 , but the hub still can't work as pas through status.

is there any other thing we need to do?

Hi,

You need to issue a USB Set_Feature(Port_Test) command to put the hub downstream port into test mode and have the hub itself sending out the test packet. For more detail, please refer to section 11.24.2.13 of the USB 2.0 specification.

If you want the hub to repeat the test packet sent by the 8155, I would recommend sending a SetPortFeature(TEST_FORCE_ENABLE) and then send the test packet SET FEATURE(TEST_MODE) from the 8155, you will then able to take the eye diagram but please note that with this approach, there will be a hub tier impact on the sync bits and EOP width that may impact the eye diagram result.

Thanks

David

David:

which port we should use ?

we tried Bus 001 Device 002: ID 0451:8027, sent TEST_FORCE_ENABLE and TEST_MODE, but couldn't get the test wave from 8155 usb 2.0 side.

Bus 002 Device 005: ID 2c7c:0455
Bus 002 Device 002: ID 0451:8025
Bus 001 Device 001: ID 1d6b:0002
Bus 001 Device 002: ID 0451:8027
Bus 002 Device 001: ID 1d6b:0003