AM625: USB Detection issue

naveenkumar Muthusamy

Part Number: AM625

Tool/software:

Hi all,

We are using Am625ALW in our systesm in which USB1 is used in host mode. we are facing issues in the usb detection. whenever an usb is connected we are getting the below logs and no usb is connected when we check using lsblk.

This is the device tree config for USb1,

&usbss1 {
    ti,vbus-divider;
    status="okay";
};

&usb1 {
    dr_mode = "host";
    status = "okay";
};

this is logs we get whenever we connect a usb device,

root@verdin-am62-15415780:~# [  354.948175] usb 1-1: new full-speed USB device number 18 using xhci-hcd
[  355.080210] usb 1-1: device descriptor read/64, error -71
[  355.320191] usb 1-1: device descriptor read/64, error -71
[  355.560196] usb 1-1: new full-speed USB device number 19 using xhci-hcd
[  355.692247] usb 1-1: device descriptor read/64, error -71
[  355.932200] usb 1-1: device descriptor read/64, error -71
[  356.044486] usb usb1-port1: attempt power cycle
[  356.460174] usb 1-1: new full-speed USB device number 20 using xhci-hcd
[  356.466927] usb 1-1: Device not responding to setup address.
[  356.680290] usb 1-1: Device not responding to setup address.
[  356.892175] usb 1-1: device not accepting address 20, error -71
[  357.024177] usb 1-1: new full-speed USB device number 21 using xhci-hcd
[  357.030923] usb 1-1: Device not responding to setup address.
[  357.244264] usb 1-1: Device not responding to setup address.
[  357.456176] usb 1-1: device not accepting address 21, error -71
[  357.462436] usb usb1-port1: unable to enumerate USB device

, below are the schamtics of the usb section,

6 months ago

0 Bin Liu 6 months ago

TI__Guru**** 170871 points

Hi Naveenkumar,

The kernel log shows USB full-speed device is detected. I guess you were not attaching a full-speed device, right? This type of issue commonly due to DM/DP signals got swapped.

Please use a scope to measure the DP and DM signals when the USB device is attached to see which line gets pulled up.

0 naveenkumar Muthusamy 6 months ago in reply to Bin Liu

Prodigy 230 points

Hi @bin_liu,

Thanks for your reply.

we usually connect a usb drive which supports full speed. we did not face this issue on the dev board. but in our custom board we are facing this issue.

we will check the DM/DP signals and let you know the details.

0 Bin Liu 6 months ago in reply to naveenkumar Muthusamy

TI__Guru**** 170871 points

Hi Naveenkumar,

Bin Liu said:
This type of issue commonly due to DM/DP signals got swapped.

This information I provided last week actually is not correct. It would be DP/DM signal swapping if the log said a low-speed device detected. But it won't be the reason if a full-speed device detected.

However, if you inserted a high-speed or super-speed device but the log shows full-speed, it still likely due to hardware design or signal integrity. So please continue check the board.

0 naveenkumar Muthusamy 6 months ago in reply to Bin Liu

Prodigy 230 points

Hi bin liu,

We are able to make the usb work now, we did some changes in the hardware.

Thanks for your support.

0 Bin Liu 6 months ago in reply to naveenkumar Muthusamy

TI__Guru**** 170871 points

Hi Naveenkumar,

Glad to hear the issue is resolved. Do you mind to explain what hardware change you made to solve the issue?

0 naveenkumar Muthusamy 6 months ago in reply to Bin Liu

Prodigy 230 points

we had a manufacturing issue in one of the boards. on other boards USB works normally non-working boards are still under debug. once resolution is found, i will update here.

0 Bin Liu 6 months ago in reply to naveenkumar Muthusamy

TI__Guru**** 170871 points

Great, looking forward to the update.

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AM625: USB Detection issue