From 1894d8f16afe5ad54b732f0fa6c4e80bd4d40b91 Mon Sep 17 00:00:00 2001 From: Keith Busch Date: Mon, 15 Jul 2013 15:02:22 -0600 Subject: NVMe: Use normal shutdown The NVMe spec recommends using the shutdown normal sequence when safely taking the controller offline instead of hitting CC.EN on the next start-up to reset the controller. The spec recommends a minimum of 1 second for the shutdown complete. This patch waits 2 seconds to be on the safe side. Signed-off-by: Keith Busch Signed-off-by: Matthew Wilcox --- drivers/block/nvme-core.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) (limited to 'drivers/block') diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c index 1595ffb..23bb5a7 100644 --- a/drivers/block/nvme-core.c +++ b/drivers/block/nvme-core.c @@ -1221,6 +1221,30 @@ static int nvme_enable_ctrl(struct nvme_dev *dev, u64 cap) return nvme_wait_ready(dev, cap, true); } +static int nvme_shutdown_ctrl(struct nvme_dev *dev) +{ + unsigned long timeout; + u32 cc; + + cc = (readl(&dev->bar->cc) & ~NVME_CC_SHN_MASK) | NVME_CC_SHN_NORMAL; + writel(cc, &dev->bar->cc); + + timeout = 2 * HZ + jiffies; + while ((readl(&dev->bar->csts) & NVME_CSTS_SHST_MASK) != + NVME_CSTS_SHST_CMPLT) { + msleep(100); + if (fatal_signal_pending(current)) + return -EINTR; + if (time_after(jiffies, timeout)) { + dev_err(&dev->pci_dev->dev, + "Device shutdown incomplete; abort shutdown\n"); + return -ENODEV; + } + } + + return 0; +} + static int nvme_configure_admin_queue(struct nvme_dev *dev) { int result; @@ -1943,6 +1967,8 @@ static void nvme_dev_shutdown(struct nvme_dev *dev) list_del_init(&dev->node); spin_unlock(&dev_list_lock); + if (dev->bar) + nvme_shutdown_ctrl(dev); nvme_dev_unmap(dev); } -- cgit v1.1