[USB HID] USBD event allocation failed! and USBD event queue full! when using battery measurement.

RE: [USB HID] USBD event allocation failed! and USBD event queue full! when using battery measurement.

Håkon Alseth — Wed, 08 May 2024 08:13:28 GMT

Hi Martin,

Always happy to help out.

In-place logging in equal or higher priority threads will delay other workqueues/threads from running, which again can be problematic especially for USB responses. It is fine to log if CONFIG_LOG_MODE_DEFERRED is set.

Kind regards,

Håkon

RE: [USB HID] USBD event allocation failed! and USBD event queue full! when using battery measurement.

Martdur — Tue, 07 May 2024 11:54:46 GMT

True !

I disabled once(because of dropped messages) and never put it back.

So as I understand too much LOG outside usb related function will delayed further LOG that are called from time sensitive function in the usb driver ?

Thanks for the help !

Regards.

Martin

RE: [USB HID] USBD event allocation failed! and USBD event queue full! when using battery measurement.

Håkon Alseth — Tue, 07 May 2024 10:23:22 GMT

Hi,

What is your LOG_MODE configured to?

If you do not log in a dedicated thread (ie. CONFIG_LOG_MODE_DEFERRED is not y-selected), in-place logging is used, which will cause a timing skew when logging from interrupt / workqueue context. This can explain the behavior that you're seeing.

You ideally want CONFIG_LOG_MODE_DEFERRED=y if you're logging from time-sensitive functions.

Kind regards,

Håkon

RE: [USB HID] USBD event allocation failed! and USBD event queue full! when using battery measurement.

Martdur — Tue, 07 May 2024 08:42:10 GMT

So I solve the issue with a quick fix :

I was measuring the battery level in a work handler trigger every x times with a timer.

In this handler I was doing

the battery measurement
Log the battery value
Log the timestamp using :
- date_time_now
- gmtime

Removing the timestamp print seems to solve the issue but this is not a normal behavior.

Is there a link between the LOG module and the USBD event queue ?

or even between date_time and the USBD event queue ?