From: Erez Shitrit <erezsh@xxxxxxxxxxxx> On fatal error the driver simulates CQE's for ULPs that rely on completion of all their posted work-request. For the GSI traffic, the mlx5 has its own mechanism that sends the completions via software CQE's directly to the relevant CQ. This should be kept in fatal error too, so the driver should simulate such CQE's with the specified error state in order to complete GSI QP work requests. Without the fix the next deadlock might appears: schedule_timeout+0x274/0x350 wait_for_common+0xec/0x240 mcast_remove_one+0xd0/0x120 [ib_core] ib_unregister_device+0x12c/0x230 [ib_core] mlx5_ib_remove+0xc4/0x270 [mlx5_ib] mlx5_detach_device+0x184/0x1a0 [mlx5_core] mlx5_unload_one+0x308/0x340 [mlx5_core] mlx5_pci_err_detected+0x74/0xe0 [mlx5_core] Cc: <stable@xxxxxxxxxxxxxxx> # 4.7 Fixes: 89ea94a7b6c4 ("IB/mlx5: Reset flow support for IB kernel ULPs") Signed-off-by: Erez Shitrit <erezsh@xxxxxxxxxxxx> Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxxxx> --- Hi, I'm sending this to rdma-next, because anyway it is going to stable@ and this is "old" bug and not important enough for -rc6. Thanks --- drivers/infiniband/hw/mlx5/cq.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/infiniband/hw/mlx5/cq.c b/drivers/infiniband/hw/mlx5/cq.c index 77d257ec899b..9f6bc34cd4db 100644 --- a/drivers/infiniband/hw/mlx5/cq.c +++ b/drivers/infiniband/hw/mlx5/cq.c @@ -637,7 +637,7 @@ static int mlx5_poll_one(struct mlx5_ib_cq *cq, } static int poll_soft_wc(struct mlx5_ib_cq *cq, int num_entries, - struct ib_wc *wc) + struct ib_wc *wc, bool is_fatal_err) { struct mlx5_ib_dev *dev = to_mdev(cq->ibcq.device); struct mlx5_ib_wc *soft_wc, *next; @@ -650,6 +650,10 @@ static int poll_soft_wc(struct mlx5_ib_cq *cq, int num_entries, mlx5_ib_dbg(dev, "polled software generated completion on CQ 0x%x\n", cq->mcq.cqn); + if (unlikely(is_fatal_err)) { + soft_wc->wc.status = IB_WC_WR_FLUSH_ERR; + soft_wc->wc.vendor_err = MLX5_CQE_SYNDROME_WR_FLUSH_ERR; + } wc[npolled++] = soft_wc->wc; list_del(&soft_wc->list); kfree(soft_wc); @@ -670,12 +674,17 @@ int mlx5_ib_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *wc) spin_lock_irqsave(&cq->lock, flags); if (mdev->state == MLX5_DEVICE_STATE_INTERNAL_ERROR) { - mlx5_ib_poll_sw_comp(cq, num_entries, wc, &npolled); + /* make sure no soft wqe's are waiting */ + if (unlikely(!list_empty(&cq->wc_list))) + soft_polled = poll_soft_wc(cq, num_entries, wc, true); + + mlx5_ib_poll_sw_comp(cq, num_entries - soft_polled, + wc + soft_polled, &npolled); goto out; } if (unlikely(!list_empty(&cq->wc_list))) - soft_polled = poll_soft_wc(cq, num_entries, wc); + soft_polled = poll_soft_wc(cq, num_entries, wc, false); for (npolled = 0; npolled < num_entries - soft_polled; npolled++) { if (mlx5_poll_one(cq, &cur_qp, wc + soft_polled + npolled)) -- 2.14.3 -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html