nvme: honor RTD3 Entry Latency for shutdowns

If an NVMe controller reports RTD3 Entry Latency larger than
shutdown_timeout, up to a maximum of 60 seconds, use that value to set
the shutdown timer. Otherwise fall back to the module parameter which
defaults to 5 seconds.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
[hch: removed do_div, made transition time local scope]
Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 1db8de0..7450589 100644 (file)
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -1458,7 +1458,7 @@ EXPORT_SYMBOL_GPL(nvme_enable_ctrl);
 
 int nvme_shutdown_ctrl(struct nvme_ctrl *ctrl)
 {
-       unsigned long timeout = jiffies + (shutdown_timeout * HZ);
+       unsigned long timeout = jiffies + (ctrl->shutdown_timeout * HZ);
        u32 csts;
        int ret;
 
@@ -1826,6 +1826,20 @@ int nvme_init_identify(struct nvme_ctrl *ctrl)
        ctrl->sgls = le32_to_cpu(id->sgls);
        ctrl->kas = le16_to_cpu(id->kas);
 
+       if (id->rtd3e) {
+               /* us -> s */
+               u32 transition_time = le32_to_cpu(id->rtd3e) / 1000000;
+
+               ctrl->shutdown_timeout = clamp_t(unsigned int, transition_time,
+                                                shutdown_timeout, 60);
+
+               if (ctrl->shutdown_timeout != shutdown_timeout)
+                       dev_warn(ctrl->device,
+                                "Shutdown timeout set to %u seconds\n",
+                                ctrl->shutdown_timeout);
+       } else
+               ctrl->shutdown_timeout = shutdown_timeout;
+
        ctrl->npss = id->npss;
        ctrl->apsta = id->apsta;
        prev_apst_enabled = ctrl->apst_enabled;

diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 2c8a02b..9b959ee 100644 (file)
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -162,6 +162,7 @@ struct nvme_ctrl {
        u16 kas;
        u8 npss;
        u8 apsta;
+       unsigned int shutdown_timeout;
        unsigned int kato;
        bool subsystem;
        unsigned long quirks;