Hariprasad S 093108cb36 RDMA/iw_cxgb4: Always wake up waiter in c4iw_peer_abort_intr() ... Currently c4iw_peer_abort_intr() does not wake up the waiter if the endpoint state indicates we're using MPAv2 and we're currently trying to connect. This was introduced with commit 7c0a33d611 ("RDMA/cxgb4: Don't wakeup threads for MPAv2") However, this original fix is flawed because it introduces a race that can cause a deadlock of the iwarp stack. Here is the race: ->local side sets up an active offload connection. ->local side sends MPA_START request. ->peer sends MPA_START response. ->local side ingress cpl thread begins processing the MPA_START response, but before it changes the state from MPA_REQ_SENT to FPDU_MODE: ->peer sends a RST which results in a ABORT_REQ_RSS. This triggers peer_abort_intr() which sees the state in MPA_REQ_SENT and since mpa_rev is 2, it will avoid waking up the endpoint with -ECONNRESET, assuming the stack will re-attempt the connection using MPAv1. ->Meanwhile, the cpl thread moves the state to FPDU_MODE and calls c4iw_modify_rc_qp() which calls rdma_init() which sends a RI_WR/INIT WR to firmware. But since HW sent an abort, FW correctly drops the RI_WR/INIT WR. ->So the cpl thread is stuck waiting for a reply and cannot process the ABORT_REQ_RSS cpl sitting in its input queue. Thus everything comes to a halt because no more ingress cpls are processed by the stack... The correct fix for the issue is to always do the wake up in c4iw_abort_intr() but reinitialize the wait object in c4iw_reconnect(). Fixes: 7c0a33d611 ("RDMA/cxgb4: Don't wakeup threads for MPAv2") Signed-off-by: Steve Wise <swise@opengridcomputing.com> Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com> Signed-off-by: Doug Ledford <dledford@redhat.com>		2016-05-13 19:38:10 -04:00
..
core	IB/security: Restrict use of the write() interface	2016-04-28 12:03:16 -04:00
hw	RDMA/iw_cxgb4: Always wake up waiter in c4iw_peer_abort_intr()	2016-05-13 19:38:10 -04:00
sw	IB/hfi1: Use global defines for upper bits in opcode	2016-04-28 16:32:28 -04:00
ulp	IB/srp: Move common code into the caller	2016-05-12 14:18:57 -04:00
Kconfig	Merge branches 'i40iw', 'sriov' and 'hfi1' into k.o/for-4.6	2016-03-21 17:32:23 -04:00
Makefile	IB/rdmavt: Create module framework and handle driver registration	2016-03-10 20:37:04 -05:00