The patch below does not apply to the 4.6-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 7049de65c9e520886f06d6f9deceaaed5d93fb7c Mon Sep 17 00:00:00 2001
From: Mike Marciniszyn <mike.marciniszyn@xxxxxxxxx>
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@xxxxxxxxxxxxxxx # 4.6+
Reviewed-by: Sebastian Sanchez <sebastian.sanchez@xxxxxxxxx>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@xxxxxxxxx>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@xxxxxxxxx>
Signed-off-by: Doug Ledford <dledford@xxxxxxxxxx>
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);
}
/**
--
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