Commit 1f390c1f authored Dec 01, 2015 by Stephan Günther Committed by Jens Axboe Dec 01, 2015

nvme: temporary fix for Apple controller reset



Recent patches added basic support for the Apple NVMe controller but
still cause resets and data corruption on that particular controller
when a specific pattern of read/flush commands occurs. Limiting the
queue depth to 2 works around that issue.

This patch enforces that limit only for the Apple controller and is
considered a temporary fix until we find the root source of that
problem.

Signed-off-by: Stephan Günther <guenther@tum.de>
Signed-off-by: Maurice Leclaire <leclaire@in.tum.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

parent dbac1175

drivers/nvme/host/pci.c

+12 −0

Original line number	Diff line number	Diff line
		@@ -2708,6 +2708,18 @@ static int nvme_dev_map(struct nvme_dev *dev)
		dev->q_depth = min_t(int, NVME_CAP_MQES(cap) + 1, NVME_Q_DEPTH);
		dev->db_stride = 1 << NVME_CAP_STRIDE(cap);
		dev->dbs = ((void __iomem *)dev->bar) + 4096;

		/*
		* Temporary fix for the Apple controller found in the MacBook8,1 and
		* some MacBook7,1 to avoid controller resets and data loss.
		*/
		if (pdev->vendor == PCI_VENDOR_ID_APPLE && pdev->device == 0x2001) {
		dev->q_depth = 2;
		dev_warn(dev->dev, "detected Apple NVMe controller, set "
		"queue depth=%u to work around controller resets\n",
		dev->q_depth);
		}

		if (readl(&dev->bar->vs) >= NVME_VS(1, 2))
		dev->cmb = nvme_map_cmb(dev);

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