Hello Mark, Thanks for your feedback. On 2/9/22 14:43, Mark Brown wrote: > On Wed, Feb 09, 2022 at 10:03:10AM +0100, Javier Martinez Canillas wrote: > >> + if (ssd130x->vbat_reg) { >> + ret = regulator_enable(ssd130x->vbat_reg); >> + if (ret) { >> + dev_err(dev, "Failed to enable VBAT: %d\n", ret); >> + return ret; >> + } >> + } > > Unless the device supports power being physically omitted regulator > usage should not be optional, it's just more code and a recipie for poor > error handling. The device has a VCC pin but in most cases this is just connected to a power provided by the board in its pinout header. For example, I've it connected to a rpi4 3.3v pin. I guess in that case what we should do then is to just have a regulator fixed as the vbat-supply in the Device Tree, that's regulator-always-on. The old ssd1307fb fbdev driver also had this as optional and I wanted to keep the new driver as backward compatible. But I understand now that is not describing the hardware properly by making this regulator optional. Best regards, -- Javier Martinez Canillas Linux Engineering Red Hat