Freeze without kernel panic

[Ahmet_Cihan_AKINCA]

Hi. We designed an imx7d based oem board and everything's working fine. However, some PCBs freeze at startup without a "kernel panic" message. We checked lots of things but cannot find the problem.

They freeze at here;

.....
[ 1.589382] usb usb2: Manufacturer: Linux 5.4.70-2.3.0+g4f2631b ehci_hcd
[ 1.596103] usb usb2: SerialNumber: ci_hdrc.1
[ 1.601131] hub 2-0:1.0: USB hub found
[ 1.604947] hub 2-0:1.0: 1 port detected

While a working one passing here like this;

....
[    1.596963] usb usb2: SerialNumber: ci_hdrc.1
[    1.602000] hub 2-0:1.0: USB hub found
[    1.605817] hub 2-0:1.0: 1 port detected
[    1.612610] input: 30370000.snvs:snvs-powerkey as /devices/soc0/soc/30000000.aips-bus/30370000.snvs/30370000.snvs:snvs-powerkey/input/input0
[    1.628315] input: TSC2007 Touchscreen as /devices/soc0/soc/30800000.aips-bus/30a20000.i2c/i2c-0/0-0048/input/input1
[    1.639609] read mpl3115 chip id 0xfffffffa
[    1.643809] mpl3115 1-0060: read chip ID 0x1 is not equal to 0xc4!
[    1.650035] mpl3115: probe of 1-0060 failed with error -22
[    1.658206] snvs_rtc 30370000.snvs:snvs-rtc-lp: registered as rtc0
[    1.664625] i2c /dev entries driver
....

We checked everything about that mentioned inputs, nothing found..

What do you think about this problem? No kernel panic, no error message, just stucking. All voltages seem fine on those PCBs. May memory IC's cause that kind of problems?

[Ahmet_Cihan_AKINCA · Accepted solution]

I solved this problem by disabling USBOTG2 in device tree. USB2 port pins are not connected anywhere in my design. Somehow, this stucks some boards. I guess we shouldn't have left these pins idle. Crashing without any kernel message is surprized me.