[PATCH 5/6] NVMe: inform block layer of write cache state

From: Jens Axboe
Date: Tue Mar 22 2016 - 13:55:58 EST


This isn't quite correct, since the VWC merely states if a potential
write back cache is volatile or not. But for the purpose of write
absortion, it's good enough.

Signed-off-by: Jens Axboe <axboe@xxxxxx>
---
drivers/nvme/host/core.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 643f457131c2..05c8edfb7611 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -906,6 +906,7 @@ static void nvme_set_queue_limits(struct nvme_ctrl *ctrl,
if (ctrl->vwc & NVME_CTRL_VWC_PRESENT)
blk_queue_flush(q, REQ_FLUSH | REQ_FUA);
blk_queue_virt_boundary(q, ctrl->page_size - 1);
+ blk_queue_write_cache(q, ctrl->vwc & NVME_CTRL_VWC_PRESENT);
}

/*
--
2.4.1.168.g1ea28e1