This is a note to let you know that I've just added the patch titled nvme-pci: don't simple map sgl when sgls are disabled to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: nvme-pci-don-t-simple-map-sgl-when-sgls-are-disabled.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 8a755954328c05f3f6bb431c13078d4eb347607a Author: Niklas Cassel <niklas.cassel@xxxxxxx> Date: Fri Apr 9 20:12:55 2021 +0200 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@xxxxxxx> Signed-off-by: Christoph Hellwig <hch@xxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index 716039ea4450..c1f3446216c5 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);