QSPI NOR power manager errrors when CONFIG_PM_DEVICE_RUNTIME is set

[Bogdan Marinescu]

I recently enabled power management in my code base by adding these two oiptions to my prj.conf:

CONFIG_PM_DEVICE=y

CONFIG_PM_DEVICE_RUNTIME=y

The code runs on an nRF5340 MCU with a LittleFS instance in an external MX25R64 QSPI flash. It all worked fine until I enabled the two options above in prj.conf, now I get this error each time the MCU starts:

<err> qspi_nor: pm_device_runtime_put failed: -16

It appears that things continue to work normally though, but I've yet to run extensive read/write tests on the external flash and the above error is a bit concerning. I also have 

CONFIG_NORDIC_QSPI_NOR_XIP=y in my prj.conf, which (among other things) is supposed to keep the external flash from sleeping if I understood correctly (I need this for various reasons). 

Does anybody know how concerned I should be about this error? Thank you.

EDIT: sorry, forgot to specify: I am using Nordic Connect SDK 2.7.0.

[Simonr]

Hi Bogdan

So I double checked with the devs regarding this, and I'm told that yyou can safely ignore this error, as it is just the QSPI letting you know it can't be powered down because of XIP being enabled. If everything works as intended you should be just fine. They will also double check the driver to make sure it's working correctly, but at first glance it seems okay.

Best regards,

Simon

[Bogdan Marinescu]

Hi Simon,

Thank you, that is reassuring. If possible, please let your developers know about the piece of code that I linked to in my previous post. It might be perfectly fine, but I think that taking another look at it doesn't hurt.

Thanks,
Bogdan