From: Sebastian Sanchez <sebastian.sanchez@xxxxxxxxx>
Check xchg returned value for queuing link down entry
to guarantee proper atomic value reads.
Fixes: 626c077c025f ("IB/hfi1: Prevent link down request double queuing")
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@xxxxxxxxx>
Signed-off-by: Sebastian Sanchez <sebastian.sanchez@xxxxxxxxx>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@xxxxxxxxx>
---
drivers/infiniband/hw/hfi1/chip.c | 18 ++++++++++++------
1 files changed, 12 insertions(+), 6 deletions(-)
diff --git a/drivers/infiniband/hw/hfi1/chip.c b/drivers/infiniband/hw/hfi1/chip.c
index 24fda52..a6c6534 100644
--- a/drivers/infiniband/hw/hfi1/chip.c
+++ b/drivers/infiniband/hw/hfi1/chip.c
@@ -7810,16 +7810,22 @@ static void handle_8051_interrupt(struct hfi1_devdata *dd, u32 unused, u64 reg)
if (queue_link_down) {
/*
* if the link is already going down or disabled, do not
- * queue another
+ * queue another. If there's a link down entry already
+ * queued, don't queue another one.
*/
if ((ppd->host_link_state &
(HLS_GOING_OFFLINE | HLS_LINK_COOLDOWN)) ||
- ppd->link_enabled == 0 || ppd->is_link_down_queued) {
- dd_dev_info(dd, "%s: not queuing link down\n",
- __func__);
+ ppd->link_enabled == 0) {
+ dd_dev_info(dd, "%s: not queuing link down. host_link_state %x, link_enabled %x\n",
+ __func__, ppd->host_link_state,
+ ppd->link_enabled);
} else {
- xchg(&ppd->is_link_down_queued, 1);
- queue_work(ppd->link_wq, &ppd->link_down_work);
+ if (xchg(&ppd->is_link_down_queued, 1) == 1)
+ dd_dev_info(dd,
+ "%s: link down request already queued\n",
+ __func__);
+ else
+ queue_work(ppd->link_wq, &ppd->link_down_work);
}
}
}
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