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-rw-r--r--drivers/nvme/host/pci.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 1b9951d2067e..d668682f91df 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -316,6 +316,14 @@ static bool nvme_dbbuf_update_and_check_event(u16 value, u32 *dbbuf_db,
old_value = *dbbuf_db;
*dbbuf_db = value;
+ /*
+ * Ensure that the doorbell is updated before reading the event
+ * index from memory. The controller needs to provide similar
+ * ordering to ensure the envent index is updated before reading
+ * the doorbell.
+ */
+ mb();
+
if (!nvme_dbbuf_need_event(*dbbuf_ei, value, old_value))
return false;
}