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 <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
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 @@
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 @@
list_del_init(&dev->node);
spin_unlock(&dev_list_lock);
+ if (dev->bar)
+ nvme_shutdown_ctrl(dev);
nvme_dev_unmap(dev);
}