diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index a67d03716510..afb99876fa9e 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -306,6 +306,14 @@ 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; }