From 7049de65c9e520886f06d6f9deceaaed5d93fb7c Mon Sep 17 00:00:00 2001 From: Mike Marciniszyn Date: Tue, 24 May 2016 12:50:23 -0700 Subject: [PATCH] IB/hfi1: Fix hard lockup due to not using save/restore spin lock Commit b9b06cb6feda ("IB/hfi1: Fix missing lock/unlock in verbs drain callback") added a spin lock. Unfortunately, the new lock code can be called from a base level interrupt state, and an interrupt that can get stacked will attempt to get the same lock. Fix by using the flag save/restore spin lock variation. Cc: stable@vger.kernel.org # 4.6+ Reviewed-by: Sebastian Sanchez Signed-off-by: Mike Marciniszyn Signed-off-by: Dennis Dalessandro Signed-off-by: Doug Ledford --- drivers/infiniband/hw/hfi1/qp.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/infiniband/hw/hfi1/qp.c b/drivers/infiniband/hw/hfi1/qp.c index 14f889e3655b..1a942ffba4cb 100644 --- a/drivers/infiniband/hw/hfi1/qp.c +++ b/drivers/infiniband/hw/hfi1/qp.c @@ -512,6 +512,7 @@ static void iowait_wakeup(struct iowait *wait, int reason) static void iowait_sdma_drained(struct iowait *wait) { struct rvt_qp *qp = iowait_to_qp(wait); + unsigned long flags; /* * This happens when the send engine notes @@ -519,12 +520,12 @@ static void iowait_sdma_drained(struct iowait *wait) * do the flush work until that QP's * sdma work has finished. */ - spin_lock(&qp->s_lock); + spin_lock_irqsave(&qp->s_lock, flags); if (qp->s_flags & RVT_S_WAIT_DMA) { qp->s_flags &= ~RVT_S_WAIT_DMA; hfi1_schedule_send(qp); } - spin_unlock(&qp->s_lock); + spin_unlock_irqrestore(&qp->s_lock, flags); } /**