TUSB8044A: TUSB8044A hot-plug fail but OK with cold-plug

Colin Liu

Part Number: TUSB8044A
Other Parts Discussed in Thread: TUSB8044

Hi Sir,

We are using TUSB8044/A as the USB3 hub, our downstream port 2 (type-A port) has been always failing hot-plug to device detection of USB3 deives but it is OK with pure U2.0 device. Another symptom is if we cold pulg the USB3 deives, then the hub can detect the device successfully. We observe this port is phsically having longer tracing and b2b connector, so we feel the issues couuld be SI relevant.

Are there any registers of the chip for us to improve it TX and RX SI to clarify?

BR,

Colin Liu

3 months ago

0 Brian Zhou 3 months ago

TI__Guru**** 159335 points

How long trace for the failed port? did it pass USB3 compliance test?

There is no register can be accessed to TX and RX SI, but we have efuse tool to increases TX swing.

Best

brian

0 Colin Liu 3 months ago

Prodigy 40 points

Hi Brian,

Sorry, we don't have resource to test the compliance or PHY now. It feels like the hub doesn't complete RX-detect or LFPS, and the ambiguity state causes hun also ignore fast-speed U2.0 connection on my type-A port

trace length ~

TUSB8044/A Hub <-> 1~2 inches <-> 5Gbps B2B connector <->5 inches <-> type-A connector

If can, we would like to check the swing or de-emphasis register to see if the root cause is the weak signal.

BR,

Colin

0 Brian Zhou 3 months ago in reply to Colin Liu

TI__Guru**** 159335 points

Please accept my friendship request to efuse tool.

Regards

Brian

0 Colin Liu 3 months ago in reply to Brian Zhou

Prodigy 40 points

Hi Brian,

the friendship request - done, please proceed.

BR,

Colin

0 Brian Zhou 3 months ago in reply to Colin Liu

TI__Guru**** 159335 points

I don't think you accepted my request.

Best

brian

0 Colin Liu 3 months ago in reply to Brian Zhou

Prodigy 40 points

sorry, I think I just accepted it correctly.

BR,

Colin

0 Brian Zhou 3 months ago in reply to Colin Liu

TI__Guru**** 159335 points

sorry, you may not accept correctly, May I have your email?

Regards

Brian

0 Colin Liu 3 months ago in reply to Brian Zhou

Prodigy 40 points

colin@pantherun.com

BR,

Colin

0 Brian Zhou 3 months ago in reply to Colin Liu

TI__Guru**** 159335 points

Please check you r email.

Best

Brian

0 Colin Liu 3 months ago in reply to Brian Zhou

Prodigy 40 points

Hi Brian,

I did clear cfgActive and (SMBUSZ pin is low), here is the log, the swing2[3:0} has no change.

root@agilex5:~# i2cset -f -y 1 0x44 0xf8 0x2
[ 2513.654824] usb 1-1: USB disconnect, device number 22
root@agilex5:~# [ 2513.659932] usb 1-1.5: USB disconnect, device number 23

root@agilex5:~# i2cget -f -y 1 0x44 0xDA
0x18
root@agilex5:~# i2cset -f -y 1 0x44 0xDA 0x1F
root@agilex5:~# i2cget -f -y 1 0x44 0xDA
0x19
root@agilex5:~# i2cset -f -y 1 0x44 0xf8 0x1
root@agilex5:~# [ 2544.330578] usb 1-1: new high-speed USB device number 24 using xhci-hcd
[ 2544.492279] hub 1-1:1.0: USB hub found
[ 2544.496210] hub 1-1:1.0: 6 ports detected
[ 2544.794549] usb 1-1.5: new high-speed USB device number 25 using xhci-hcd
[ 2544.905031] hid-generic 0003:0451:82FF.000C: device has no listeners, quitting

root@agilex5:~# i2cget -f -y 1 0x44 0xDA
0x19
root@agilex5:~#

BR,

Colin

0 Brian Zhou 3 months ago in reply to Colin Liu

TI__Guru**** 159335 points

Hi Colin:

How did you check swing not changing since USB3 didn't work?

Best

Brian

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TUSB8044A: TUSB8044A hot-plug fail but OK with cold-plug