Update broken my Wolfson

[fruit-uk]

I did a standard apt update yesterday and now my Wolfson Pi sound has disappeared!
It's running ragnar's 3.18 kernel from earlier this year but I'm now seeing

Code: Select all

[   10.135474] arizona spi0.1: Failed to find supply LDOVDD
[   10.497614] arizona spi0.1: Failed to register LDO1 supply: -517
[   10.576357] platform arizona-ldo1: Driver arizona-ldo1 requests probe deferral
[   10.685181] arizona spi0.1: Failed to get supply 'AVDD': -517
[   10.805004] arizona spi0.1: Failed to request core supplies: -517
[   10.906370] spi spi0.1: Driver arizona requests probe deferral
[   11.038370] LDO1: 1200 <--> 1800 mV at 1200 mV 
[   11.044990] arizona spi0.1: Failed to find supply LDOVDD
[   11.076919] arizona spi0.1: Failed to register LDO1 supply: -517
[   11.084878] platform arizona-ldo1: Driver arizona-ldo1 requests probe deferral
[   11.094383] DC_1V8: 1800 mV 
[   11.123493] spi0.1 supply DCVDD not found, using dummy regulator
[   11.144914] DC_5V: 5000 mV 
[   11.156592] arizona spi0.1: Unknown device ID: 0
[   12.523982] snd-rpi-wsp sound: ASoC: CODEC DAI wm5102-aif1 not registered
[   12.532878] snd-rpi-wsp sound: Failed to register card: -517
[   12.540519] platform sound: Driver snd-rpi-wsp requests probe deferral
[   14.095031] snd-rpi-wsp sound: ASoC: CODEC DAI wm5102-aif1 not registered
[   14.107672] snd-rpi-wsp sound: Failed to register card: -517
[   14.115314] platform sound: Driver snd-rpi-wsp requests probe deferral

What has changed?

Edit:
It seems the update overwrote files in /boot. Although I think this has happened before and not caused problems, this time it did!
Solution was to copy /boot files from another SD card with an older install, making sure those files required by the Wolfson remained ie. cmdline.txt, config.txt, the Wolfson kernel and overlay