Interrupt-driven link status feedback mechanism for embedded switches

A tangible computer readable medium having a computer program product encoded thereon for intelligently propagating link status information in a blade server, the computer readable medium comprising:

• computer usable instructions for identifying a communication loss between an external switch module and a multi-port switch of a blade server, wherein the communication loss is identified by an intermediate bus controller;
• computer usable instructions, responsive to identifying the communication loss between the external switch module and the multi-port switch of the blade server, generating a link down interrupt wherein the link down interrupt is generated by the intermediate bus controller;
• and
• computer usable instructions, responsive to generating the link down interrupt, for broadcasting the link down interrupt from the intermediate bus controller to a server blade of the blade server.

A data processing system comprising:

• a bus;
• a communications unit connected to the bus;
• a memory connected to the bus, wherein the memory includes a computer usable code for propagating link status information in a blade server;
• and
• a processor unit connected to the bus, wherein the processor unit executes the computer usable code to identify a communication loss between an external switch module and a multi-port switch of a blade server, wherein the communication loss is identified by an intermediate bus controller;
• responsive to identifying the communication loss between the external switch module and the multi-port switch of the blade server, to generate a link down interrupt wherein the link down interrupt is generated by the intermediate bus controller;
• and responsive to generating the link down interrupt, to broadcast the link down interrupt from the intermediate bus controller to a server blade of the blade server.

A computer implemented method for propagating link status information in a blade server, the method comprising the computer implemented steps of:

• identifying a communication loss between an external switch module and a multi-port switch of a blade server, wherein the communication loss is identified by an intermediate bus controller, and wherein the communication loss is a disconnect of the external switch module from an outside network, wherein the external switch is a hot-swappable switch that connects a server blade of the blade server to the outside network;
• responsive to identifying the communication loss between the external switch module and the multi-port switch of the blade server, generating a link down interrupt wherein the link down interrupt is generated by the intermediate bus controller;
• and
• responsive to generating the link down interrupt, broadcasting the link down interrupt from the intermediate bus controller to the server blade of the blade server.
• receiving the link down interrupt from the intermediate bus controller at a multi-port switch of the server blade;
• responsive to receiving the link down interrupt from the intermediate bus controller, generating a hardware link down interrupt, wherein the hardware link down interrupt is generated by the multi-port switch;
• identifying at least one port of the multi-port switch the hardware link down interrupt is to be sent to, wherein the at least one port is identified from a multi-port switch register, wherein the multi-port switch register is a hardware register that stores at least one condition under which the hardware link down interrupt should be forwarded to the connected unit;
• responsive to generating the hardware link down interrupt, forwarding the hardware link down interrupt from the multi-port switch to a connected unit, wherein the connected unit is selected from the group consisting of a service firmware and a server blade operating system, wherein the connected unit is connected to the at least one port, wherein the hardware link down interrupt is forwarded for every link down interrupt that is received by multi-port switch or wherein the hardware link down interrupt is forwarded only if the link down interrupt is not followed by a link up event within a certain period of time.

An apparatus comprising:

• a chassis;
• a number of server blades located within the chassis;
• an intermediate bus controller, wherein the intermediate bus controller is capable of identifying a communication loss between an external switch module and a multi-port switch of a blade server;
• generating a link down interrupt wherein the link down interrupt is generated by the intermediate bus controller;
• and responsive to generating the link down interrupt, broadcasting the link down interrupt from the intermediate bus controller to the number of server blades.