1.5.4 crashes....

[Bas ON5HB]

Just had a crash, did happen a few times before.

traps: spectrumserver[141947] general protection fault ip:55880a042f60 sp:7f0655cba6c0 error:0 in spectrumserver[558809f7e000+db000]

I found that error:0 implies a devide by zero in the code.

[Bas ON5HB]

I have looked in the code you changed....and I found this....can this be the problem?

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float peak_sample = max();

            float desired_gain = std::min(desired_level / (peak_sample + 1e-15f), max_gain);

Not sure, but if the (peak_sample + 1e-15f) part becomes 0 it could happen.

No idea if it helps. Found it in utils/audioprocessing.cpp

[magicint1337]

The + 1e-15f is only there to make it never divide through zero

[Bas ON5HB]

Why not check if peaksample is 0? If so make it the value 1e-15f.

Then it can never be 0. The way you do it now can cause 0 because of rounding.

Small chance it does, but I do believe it happens from time to time and causing the spectrumserver to crash.

You're way it can become 0 when peak_sample is -1e-15f, counted together they become 0.

Just a thought, I normally don't program with floating because of these problems.

[magicint1337]

Very rare edge case, may happen but you cant just dont code with floating point because of that. Especially not in DSP

In future version will be changed.

[Bas ON5HB]

I code in drivers, like the Airspy_tcp or the RSP_tcp, they do not need floating to output 8bit

[Bas ON5HB]

That didn't take long, it crashed again, took less then 10 minutes:

[30847.925132] traps: spectrumserver[141947] general protection fault ip:55880a042f60 sp:7f0655cba6c0 error:0 in spectrumserver[558809f7e000+db000]

Location is the same....so it must be happening elsewhere....

[Bas ON5HB]

And again....it's happening faster now...every few minutes...

That is good...

[Bas ON5HB]

I have noticed that when it happens the RX888 is having messages in dmesg...

It may not be related but the USB ports where on auto-powersafe (=default!)...so I turned them ON all the time in my start-script.

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# Turn USB on all the time.
echo on | sudo tee /sys/bus/usb/devices/*/power/control > /dev/null