Commit 5b2c214a authored by Keith Busch's avatar Keith Busch Committed by Christoph Hellwig
Browse files

nvme-pci: try function level reset on init failure 



NVMe devices from multiple vendors appear to get stuck in a reset state
that we can't get out of with an NVMe level Controller Reset. The kernel
would report these with messages that look like:

  Device not ready; aborting reset, CSTS=0x1

These have historically required a power cycle to make them usable
again, but in many cases, a PCIe FLR is sufficient to restart operation
without a power cycle. Try it if the initial controller reset fails
during any nvme reset attempt.

Signed-off-by: default avatarKeith Busch <kbusch@kernel.org>
Reviewed-by: default avatarChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: default avatarNitesh Shetty <nj.shetty@samsung.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
parent 746d0ac5

drivers/nvme/host/pci.c

+22 −2
Original line number Diff line number Diff line
@@ -2064,9 +2064,29 @@ static int nvme_pci_configure_admin_queue(struct nvme_dev *dev) 
	 * might be pointing at!

	 */

	result = nvme_disable_ctrl(&dev->ctrl, false);

	if (result < 0) {

		struct pci_dev *pdev = to_pci_dev(dev->dev);



		/*

		 * The NVMe Controller Reset method did not get an expected

		 * CSTS.RDY transition, so something with the device appears to

		 * be stuck. Use the lower level and bigger hammer PCIe

		 * Function Level Reset to attempt restoring the device to its

		 * initial state, and try again.

		 */

		result = pcie_reset_flr(pdev, false);

		if (result < 0)

			return result;



		pci_restore_state(pdev);

		result = nvme_disable_ctrl(&dev->ctrl, false);

		if (result < 0)

			return result;



		dev_info(dev->ctrl.device,

			"controller reset completed after pcie flr\n");

	}



	result = nvme_alloc_queue(dev, 0, NVME_AQ_DEPTH);

	if (result)

		return result;