RDMA/ocrdma: EQ full catastrophe avoidance
Stale entries in the CQ being destroyed causes hardware to generate
EQEs indefinitely for a given CQ. Thus causing uncontrolled execution
of irq_handler. This patch fixes this using following sementics:
* irq_handler will ring EQ doorbell atleast once and implement budgeting scheme.
* cq_destroy will count number of valid entires during destroy and ring
cq-db so that hardware does not generate uncontrolled EQE.
* cq_destroy will synchronize with last running irq_handler instance.
* arm_cq will always defer arming CQ till poll_cq, except for the first arm_cq call.
* poll_cq will always ring cq-db with arm=SET if arm_cq was called prior to enter poll_cq.
* poll_cq will always ring cq-db with arm=UNSET if arm_cq was not called prior to enter poll_cq.
Signed-off-by: Devesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: Selvin Xavier <selvin.xavier@emulex.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
4 files changed