MPSL disabling USB interrupts

RE: MPSL disabling USB interrupts

Einar Thorsrud — Tue, 07 Oct 2025 11:29:58 GMT

Hi,

This will be fixed in nRF Connect SDK 3.2.0 (and is currently fixed in main).

RE: MPSL disabling USB interrupts

Einar Thorsrud — Mon, 08 Sep 2025 08:09:35 GMT

Hi,

The MPSL itself does not disconnect interrupts in the NVIC, but it disables the enabled interrupts in POWER/CLOCK regsiter and do not re-enable any. So any that you need (for instance for USB in this case), needs to be re-enabled.

RE: MPSL disabling USB interrupts

AGeegee — Fri, 05 Sep 2025 10:47:21 GMT

Hi Einar,

Thanks for confirming that. How does the MPSL affect the POWER/CLOCK interrupt?

Does it disconnect / reconnect existing IRQs?

Using Zephyr, there is a

"nrfx_power_clock_irq_handler"

Seeing as this calls the MPSL POWER IRQ handler, just want to confirm that no additional IRQs for POWER/CLOCK need to be CONNECTED before and after mpsl_lib_init/uninit.

RE: MPSL disabling USB interrupts

Einar Thorsrud — Fri, 05 Sep 2025 08:25:01 GMT

Hi,

I confirm that the behaviour you see is part of the MPSL binary, and that all POWER interrupts are disabled. We are looking into if this can be done differently, but for the short term there is no solution other than re-enabling immediately after disabling MPSL as a (non-perfect) workaround as the MPSL is distributed as a binary library.

RE: MPSL disabling USB interrupts

Einar Thorsrud — Wed, 03 Sep 2025 12:08:27 GMT

Hi,

I reproduce the same on my end. We are looking into this and I will get back to you.

RE: MPSL disabling USB interrupts

AGeegee — Tue, 02 Sep 2025 12:37:50 GMT

SET the POWER.INTENSET interrupts to 1. Then call mpsl_uninit followed by mpsl_init. Observe the POWER.INTENSET registers and note that the interrupt enables are cleared.

RE: MPSL disabling USB interrupts

Einar Thorsrud — Tue, 02 Sep 2025 12:31:13 GMT

Hi,

I have not seen any other such issues reported, and looking at the code I do not find any instances where MPSL writes to the POWER registers. Can you share more details about how you see and reproduce this?