How do you undo unpowering a device?

[tyilo]

Specifically I'm interested in my SD card reader.

Is the only option to reboot my system or can I run some command to power it on again?

[coldfix]

Hi,

there is nothing in udisks as far as I know, but you could try usbreset or try rescanning.

(and of course unplug/replug the device, but I assume you were excluding that option intentionally too)