BUG: kernel NULL pointer dereference, address

RE: BUG: kernel NULL pointer dereference, address

PeterRasmussen — Tue, 22 Feb 2022 15:16:05 GMT

Its a laptop so i did the test without anything connected

RE: BUG: kernel NULL pointer dereference, address

tesc — Tue, 22 Feb 2022 14:37:36 GMT

Hi,

Thanks for the update. Too bad the MSD workaround doesn't work. We have multiple users of the same version of Ubuntu in-house, and do not see the issue here, which does point in the direction of the specific hardware of your laptop in combination with the given driver.

One final thought: Have you added (or briefly used) any other USB devices to your system lately, that can somehow have led to a conflict?

Regards,
Terje

RE: BUG: kernel NULL pointer dereference, address

PeterRasmussen — Tue, 22 Feb 2022 12:43:20 GMT

Hey

I actually have tried to disable MSDDisable and it does not seems to be the problem.

I have also raised the same bug at Lenovo. I have also tried to submit the bug to Ubuntu but that was easier said than done and i dont know if i have submitted it correctly.

RE: BUG: kernel NULL pointer dereference, address

tesc — Tue, 22 Feb 2022 12:36:26 GMT

Hi,

The Linux USB driver crashing on removing a USB device sounds like a Linux USB driver issue. It is hard to tell from our end what might be the issue there, and we are not able to reproduce locally using the same Ubuntu distribution. If you haven't done so already, I recommend checking with Linux and/or Ubuntu forums / support in order to figure out what is the issue, or if it is a driver provided and supported by a hardware manufacturer contact them about the issue.

From our side, one thing you could try is use J-Link Commander and issue the command "MSDDisable", for disabling the Mass Storage Device functionality of the SEGGER interface MCU. If the driver issue is in any way related to the MSD functionality, then that might provide a workaround. The MSD functionality is not used for any of the standard workflows when working with nRF devices.

Regards,
Terje