From: Devesh Sharma Date: Tue, 4 Feb 2014 06:26:54 +0000 (+0530) Subject: RDMA/ocrdma: EQ full catastrophe avoidance X-Git-Tag: v3.15-rc1~103^2^8~17 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ea61762679cd4d409dcaa6f502f190f4c8156d09;p=pandora-kernel.git 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 Signed-off-by: Selvin Xavier Signed-off-by: Roland Dreier --- Reading git-diff-tree failed