diff options
authorGuilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>2016-06-14 18:22:41 -0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-06-29 12:48:53 +0200
commitbddc80274a128596876f8aad29afb875183c993c (patch)
parente5f87c73384279f005d9bb27bed03a29335c3492 (diff)
nvme/quirk: Add a delay before checking for adapter readiness
commit 54adc01055b75ec8769c5a36574c7a0895c0c0b2 upstream. When disabling the controller, the specification says the register NVME_REG_CC should be written and then driver needs to wait the adapter to be ready, which is checked by reading another register bit (NVME_CSTS_RDY). There's a timeout validation in this checking, so in case this timeout is reached the driver gives up and removes the adapter from the system. After a firmware activation procedure, the PCI_DEVICE(0x1c58, 0x0003) (HGST adapter) end up being removed if we issue a reset_controller, because driver keeps verifying the NVME_REG_CSTS until the timeout is reached. This patch adds a necessary quirk for this adapter, by introducing a delay before nvme_wait_ready(), so the reset procedure is able to be completed. This quirk is needed because just increasing the timeout is not enough in case of this adapter - the driver must wait before start reading NVME_REG_CSTS register on this specific device. Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com> [mauricfo: backport to v4.4.70 without nvme quirk handling & nvme_ctrl] Signed-off-by: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com> Tested-by: Narasimhan Vaidyanathan <vnarasimhan@in.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2 files changed, 17 insertions, 0 deletions
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 044253dca30a..b8a5a8e8f57d 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -27,6 +27,13 @@ enum {
+/* The below value is the specific amount of delay needed before checking
+ * readiness in case of the PCI_DEVICE(0x1c58, 0x0003), which needs the
+ * NVME_QUIRK_DELAY_BEFORE_CHK_RDY quirk enabled. The value (in ms) was
+ * found empirically.
+ */
* Represents an NVM Express device. Each nvme_dev is a PCI function.
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index c851bc53831c..e9750a0a6f2c 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1633,10 +1633,20 @@ static int nvme_wait_ready(struct nvme_dev *dev, u64 cap, bool enabled)
static int nvme_disable_ctrl(struct nvme_dev *dev, u64 cap)
+ struct pci_dev *pdev = to_pci_dev(dev->dev);
dev->ctrl_config &= ~NVME_CC_SHN_MASK;
dev->ctrl_config &= ~NVME_CC_ENABLE;
writel(dev->ctrl_config, &dev->bar->cc);
+ /* Checking for dev->tagset is a trick to avoid sleeping on module
+ * load, since we only need the quirk on reset_controller. Notice
+ * that the HGST device needs this delay only in firmware activation
+ * procedure; unfortunately we have no (easy) way to verify this.
+ */
+ if (pdev->vendor == 0x1c58 && pdev->device == 0x0003 && dev->tagset)
return nvme_wait_ready(dev, cap, false);