On Sun, May 24, 2026 at 10:05:33AM +0200, Paul Menzel wrote:

Some platforms (e.g. IBM Power System S822LC (8335-GCA POWER8)) do not
describe the EEPROM’s VCC supply in firmware-provided device trees.
Using `devm_regulator_get()` on such systems falls back to a dummy
regulator with a kernel warning:

Switch to `devm_regulator_get_optional()` and treat -ENODEV as “no
supply described”. When `vcc_reg` is NULL, skip all
regulator_enable/disable calls; the hardware is assumed to be always
powered. Linux now logs:

This is not appropriate unless the device can actually operate without
power, any driver could be used in a system where the firmware does not
describe the regultors and it'd obviously be pointless and error prone
to scatter bodges like this on every single call to a regulator API
function.