I can also confirm this issue on my XPS M1330 running 9.10. Plug in mic works fine as either mic 1 or mic 2, but internal mic is not even shown as an option. The workaround mentioned using sudo alsamixer does not work for me as alsamixer does not show entry for digital mic either. It almost seems that the hardware is not recognized. It worked previous versions although at low volume,
I can also confirm this issue on my XPS M1330 running 9.10. Plug in mic works fine as either mic 1 or mic 2, but internal mic is not even shown as an option. The workaround mentioned using sudo alsamixer does not work for me as alsamixer does not show entry for digital mic either. It almost seems that the hardware is not recognized. It worked previous versions although at low volume,