[PATCH 1/3] nvme: support command retry delay for admin command

[Minwoo Im]

Once driver decides to retry a command that failed, it can have some
delay based on Command Retry Delay(CRD) in Completion Queue Entry.  If
CRD indicates Command Retry Delay Time 1, 2, or 3, driver calcualtes
delay in Identify Controller data structure.

This feature can be applied not only I/O queue commands, but also admin
queue commands.  Admin command during the initialization may fail due to
some un-ready state of a controller, so it would be better to have this
feature for admin commands also.

This patch simply removed getting namespace instance(struct nvme_ns) from
the struct request and get a controller instance(struct nvme_ctrl) by
nvme_req() helper.  Now, nvme_retry_req() calculates the delay
regardless to namespace instance which meant this request is for I/O
command.

Signed-off-by: Minwoo Im <minwoo.im.dev at gmail.com>
---
 drivers/nvme/host/core.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index ce1b61519441..d0c99a9400ea 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -280,14 +280,13 @@ static blk_status_t nvme_error_status(u16 status)
 
 static void nvme_retry_req(struct request *req)
 {
-	struct nvme_ns *ns = req->q->queuedata;
 	unsigned long delay = 0;
 	u16 crd;
 
 	/* The mask and shift result must be <= 3 */
 	crd = (nvme_req(req)->status & NVME_SC_CRD) >> 11;
-	if (ns && crd)
-		delay = ns->ctrl->crdt[crd - 1] * 100;
+	if (crd)
+		delay = nvme_req(req)->ctrl->crdt[crd - 1] * 100;
 
 	nvme_req(req)->retries++;
 	blk_mq_requeue_request(req, false);
-- 
2.17.1