nvme: Respect timeout when en/disabling the controller
So far the driver unconditionally delays 10ms when en/disabling the
controller and still return 0 if 10ms times out. In fact, spec defines
a timeout value in the CAP register that is the worst case time that
host software shall wait for the controller to become ready.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/drivers/nvme/nvme.c b/drivers/nvme/nvme.c
index d92273e..8867977 100644
--- a/drivers/nvme/nvme.c
+++ b/drivers/nvme/nvme.c
@@ -47,11 +47,19 @@
static int nvme_wait_ready(struct nvme_dev *dev, bool enabled)
{
u32 bit = enabled ? NVME_CSTS_RDY : 0;
+ int timeout;
+ ulong start;
- while ((readl(&dev->bar->csts) & NVME_CSTS_RDY) != bit)
- udelay(10000);
+ /* Timeout field in the CAP register is in 500 millisecond units */
+ timeout = NVME_CAP_TIMEOUT(dev->cap) * 500;
+
+ start = get_timer(0);
+ while (get_timer(start) < timeout) {
+ if ((readl(&dev->bar->csts) & NVME_CSTS_RDY) == bit)
+ return 0;
+ }
- return 0;
+ return -ETIME;
}
static int nvme_setup_prps(struct nvme_dev *dev, u64 *prp2,