This adds support for hot adding and removing expanders, and its associated attached devices. When there is a change in topology, the fusion firmware sends the MPI_EVENT_SAS_DISCOVERY event to the driver. The driver will read firmware config pages to determine what changes took place, and refresh drivers view of the world stored in ioc->sas_topology. Here is the details of the action the driver does: (1) Expander Added : The mptsas_discovery_work workqueue is called. Config pages read, and ioc->sas_topology is refreshed. The sas_phy_add() is called for each phy of the expander. The expanders attached devices are added via sas_rphy_add(). Added end devices are handled within the MPT_ADD_DEVICE logic in mptsas_hotplug_work workqueue. (2) Expander Delete : The sas_rphy_delete() will be called for the top most compenent of the parent that the expander is attached to. The sas_rphy_delete call will delete all the children phys, rphys, and end devices. This is handled from mptsas_discovery_work workqueue. Signed-off-by: Eric Moore <Eric.Moore@xxxxxxxx>
Attachment:
9_expander_hotplug.patch
Description: 9_expander_hotplug.patch
