I have an Asus X555L, on the right side there is a usb port and a jack port, sometimes i put my headphones' plug to the usb port but i didnt have any issues. Now I accidentally did it again and smoke came out of the usb port with a strong burning smell. I instantly pushed the power button, howewer i only put it into sleeping mode and now the laptop is ok. It is now switched off.
I dont dare using it now because the port still smells like burning plastic.
might as well turn the laptop on to see if it will load windows or not. right now you most likely fried that usb port, hopefully only that port because some of your other devices use usb like your onboard webcam & I think the touchpad.