From 22605f96810d073eb74051d0295b6577d6a6a563 Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Tue, 19 Apr 2011 15:04:20 -0400 Subject: [PATCH] NVMe: Time out initialisation after a few seconds THe device reports (in its capability register) how long it will take to initialise. If that time elapses before the ready bit becomes set, conclude the device is broken and refuse to initialise it. Log a nice error message so the user knows why we did nothing. Signed-off-by: Matthew Wilcox --- drivers/block/nvme.c | 10 ++++++++++ include/linux/nvme.h | 2 ++ 2 files changed, 12 insertions(+) diff --git a/drivers/block/nvme.c b/drivers/block/nvme.c index bcc780a..57f2b33a 100644 --- a/drivers/block/nvme.c +++ b/drivers/block/nvme.c @@ -893,6 +893,8 @@ static int __devinit nvme_configure_admin_queue(struct nvme_dev *dev) { int result; u32 aqa; + u64 cap; + unsigned long timeout; struct nvme_queue *nvmeq; dev->dbs = ((void __iomem *)dev->bar) + 4096; @@ -915,10 +917,18 @@ static int __devinit nvme_configure_admin_queue(struct nvme_dev *dev) writeq(nvmeq->cq_dma_addr, &dev->bar->acq); writel(dev->ctrl_config, &dev->bar->cc); + cap = readq(&dev->bar->cap); + timeout = ((NVME_CAP_TIMEOUT(cap) + 1) * HZ / 2) + jiffies; + while (!(readl(&dev->bar->csts) & NVME_CSTS_RDY)) { msleep(100); if (fatal_signal_pending(current)) return -EINTR; + if (time_after(jiffies, timeout)) { + dev_err(&dev->pci_dev->dev, + "Device not ready; aborting initialisation\n"); + return -ENODEV; + } } result = queue_request_irq(dev, nvmeq, "nvme admin"); diff --git a/include/linux/nvme.h b/include/linux/nvme.h index 9d6febb..a19304f 100644 --- a/include/linux/nvme.h +++ b/include/linux/nvme.h @@ -35,6 +35,8 @@ struct nvme_bar { __u64 acq; /* Admin CQ Base Address */ }; +#define NVME_CAP_TIMEOUT(cap) (((cap) >> 24) & 0xff) + enum { NVME_CC_ENABLE = 1 << 0, NVME_CC_CSS_NVM = 0 << 4, -- 2.7.4