Transition into and out of a partially-off power state

A computer system comprising:

• a serial bus controller to control at least one serial bus port;
• and
• wherein the computer system is responsive to a first trigger event to enter a partial off state in which a boot cycle is required to return the computer system to a working state and the computer system is responsive to a power switch being pressed to return to a working state and in the partial off state the computer system is configured to supply charging current to a device plugged into the serial bus port;
• and
• wherein the computer system is responsive to a second trigger event while in the partial off state to return to the working state.

A computer system comprising:

• a serial port to supply a charging current to a device plugged into the serial port while the computer system is in a partial off state;
• a charging circuit to supply the charging current in the partial off state;
• a configuration register;
• wherein the computer system is responsive to a first trigger event and a first setting of the configuration register to enter the partial off state;
• wherein the computer system is responsive to the first trigger event and a second setting of the configuration register to enter a shut down state instead of the partial off state;
• and
• wherein the partial off state is a power state in which a boot cycle is required to return the computer system to a working state and the computer system is responsive to a power switch being pressed to return to a working state.