Commit 29900bf3 authored by Selvin Xavier's avatar Selvin Xavier Committed by Leon Romanovsky
Browse files

RDMA/bnxt_re: Fix hang during driver unload 



Driver unload hits a hang during stress testing of load/unload.

stack trace snippet -

tasklet_kill at ffffffff9aabb8b2
bnxt_qplib_nq_stop_irq at ffffffffc0a805fb [bnxt_re]
bnxt_qplib_disable_nq at ffffffffc0a80c5b [bnxt_re]
bnxt_re_dev_uninit at ffffffffc0a67d15 [bnxt_re]
bnxt_re_remove_device at ffffffffc0a6af1d [bnxt_re]

tasklet_kill can hang if the tasklet is scheduled after it is disabled.

Modified the sequences to disable the interrupt first and synchronize
irq before disabling the tasklet.

Fixes: 1ac5a404 ("RDMA/bnxt_re: Add bnxt_re RoCE driver")
Signed-off-by: default avatarKashyap Desai <kashyap.desai@broadcom.com>
Signed-off-by: default avatarSelvin Xavier <selvin.xavier@broadcom.com>
Link: https://lore.kernel.org/r/1689322969-25402-3-git-send-email-selvin.xavier@broadcom.com


Signed-off-by: default avatarLeon Romanovsky <leon@kernel.org>
parent b5bbc655

drivers/infiniband/hw/bnxt_re/qplib_fp.c

+5 −5
Original line number Diff line number Diff line
@@ -420,19 +420,19 @@ void bnxt_qplib_nq_stop_irq(struct bnxt_qplib_nq *nq, bool kill) 
	if (!nq->requested)

		return;



	tasklet_disable(&nq->nq_tasklet);

	nq->requested = false;

	/* Mask h/w interrupt */

	bnxt_qplib_ring_nq_db(&nq->nq_db.dbinfo, nq->res->cctx, false);

	/* Sync with last running IRQ handler */

	synchronize_irq(nq->msix_vec);

	if (kill)

		tasklet_kill(&nq->nq_tasklet);



	irq_set_affinity_hint(nq->msix_vec, NULL);

	free_irq(nq->msix_vec, nq);

	kfree(nq->name);

	nq->name = NULL;

	nq->requested = false;



	if (kill)

		tasklet_kill(&nq->nq_tasklet);

	tasklet_disable(&nq->nq_tasklet);

}



void bnxt_qplib_disable_nq(struct bnxt_qplib_nq *nq)

drivers/infiniband/hw/bnxt_re/qplib_rcfw.c

+4 −5
Original line number Diff line number Diff line
@@ -989,19 +989,18 @@ void bnxt_qplib_rcfw_stop_irq(struct bnxt_qplib_rcfw *rcfw, bool kill) 
	if (!creq->requested)

		return;



	tasklet_disable(&creq->creq_tasklet);

	creq->requested = false;

	/* Mask h/w interrupts */

	bnxt_qplib_ring_nq_db(&creq->creq_db.dbinfo, rcfw->res->cctx, false);

	/* Sync with last running IRQ-handler */

	synchronize_irq(creq->msix_vec);

	if (kill)

		tasklet_kill(&creq->creq_tasklet);



	free_irq(creq->msix_vec, rcfw);

	kfree(creq->irq_name);

	creq->irq_name = NULL;

	creq->requested = false;

	atomic_set(&rcfw->rcfw_intr_enabled, 0);

	if (kill)

		tasklet_kill(&creq->creq_tasklet);

	tasklet_disable(&creq->creq_tasklet);

}



void bnxt_qplib_disable_rcfw_channel(struct bnxt_qplib_rcfw *rcfw)