From a11497b3bb7546db5a982ccf8bc36a1f30aa4a6f Mon Sep 17 00:00:00 2001
From: Niklas Cassel <niklas.cassel@wdc.com>
Date: Fri, 9 Apr 2021 20:12:55 +0200
Subject: [PATCH] nvme-pci: don't simple map sgl when sgls are disabled
[ Upstream commit e51183be1fa96dc6d3cd11b3c25a0f595807315e ]
According to the module parameter description for sgl_threshold,
a value of 0 means that SGLs are disabled.
If SGLs are disabled, we should respect that, even for the case
where the request is made up of a single physical segment.
Fixes: 297910571f08 ("nvme-pci: optimize mapping single segment requests using SGLs")
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/nvme/host/pci.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 716039ea4450eb..c1f3446216c5ce 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -852,7 +852,7 @@ static blk_status_t nvme_map_data(struct nvme_dev *dev, struct request *req,
return nvme_setup_prp_simple(dev, req,
&cmnd->rw, &bv);
- if (iod->nvmeq->qid &&
+ if (iod->nvmeq->qid && sgl_threshold &&
dev->ctrl.sgls & ((1 << 0) | (1 << 1)))
return nvme_setup_sgl_simple(dev, req,
&cmnd->rw, &bv);
--
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