From 54adc01055b75ec8769c5a36574c7a0895c0c0b2 Mon Sep 17 00:00:00 2001 From: "Guilherme G. Piccoli" Date: Tue, 14 Jun 2016 18:22:41 -0300 Subject: [PATCH] nvme/quirk: Add a delay before checking for adapter readiness 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 Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe --- drivers/nvme/host/core.c | 9 +++++++++ drivers/nvme/host/nvme.h | 13 +++++++++++++ drivers/nvme/host/pci.c | 2 ++ 3 files changed, 24 insertions(+) diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index 500b790..a51946a 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -1109,6 +1109,15 @@ int nvme_disable_ctrl(struct nvme_ctrl *ctrl, u64 cap) ret = ctrl->ops->reg_write32(ctrl, NVME_REG_CC, ctrl->ctrl_config); if (ret) return ret; + + /* Checking for ctrl->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 ((ctrl->quirks & NVME_QUIRK_DELAY_BEFORE_CHK_RDY) && ctrl->tagset) + msleep(NVME_QUIRK_DELAY_AMOUNT); + return nvme_wait_ready(ctrl, cap, false); } EXPORT_SYMBOL_GPL(nvme_disable_ctrl); diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h index abe83b4..1bd42d5 100644 --- a/drivers/nvme/host/nvme.h +++ b/drivers/nvme/host/nvme.h @@ -68,8 +68,21 @@ enum nvme_quirks { * logical blocks. */ NVME_QUIRK_DISCARD_ZEROES = (1 << 2), + + /* + * The controller needs a delay before starts checking the device + * readiness, which is done by reading the NVME_CSTS_RDY bit. + */ + NVME_QUIRK_DELAY_BEFORE_CHK_RDY = (1 << 3), }; +/* 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. + */ +#define NVME_QUIRK_DELAY_AMOUNT 2000 + enum nvme_ctrl_state { NVME_CTRL_NEW, NVME_CTRL_LIVE, diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index 79a4f56..846a429 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -2094,6 +2094,8 @@ static const struct pci_device_id nvme_id_table[] = { NVME_QUIRK_DISCARD_ZEROES, }, { PCI_VDEVICE(INTEL, 0x5845), /* Qemu emulated controller */ .driver_data = NVME_QUIRK_IDENTIFY_CNS, }, + { PCI_DEVICE(0x1c58, 0x0003), /* HGST adapter */ + .driver_data = NVME_QUIRK_DELAY_BEFORE_CHK_RDY, }, { PCI_DEVICE_CLASS(PCI_CLASS_STORAGE_EXPRESS, 0xffffff) }, { PCI_DEVICE(PCI_VENDOR_ID_APPLE, 0x2001) }, { 0, } -- 2.7.4