Commit fb0dc399 authored by Andy Lutomirski's avatar Andy Lutomirski Committed by Jens Axboe
Browse files

nvme: Display raw APST configuration via DYNAMIC_DEBUG 



Debugging APST is currently a bit of a pain.  This gives optional
simple log messages that describe the APST state.

The easiest way to use this is probably with the nvme_core.dyndbg=+p
module parameter.

Signed-off-by: default avatarAndy Lutomirski <luto@kernel.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent 76e4ad09

drivers/nvme/host/core.c

+16 −0
Original line number Diff line number Diff line
@@ -1336,6 +1336,8 @@ static void nvme_configure_apst(struct nvme_ctrl *ctrl) 


	unsigned apste;

	struct nvme_feat_auto_pst *table;

	u64 max_lat_us = 0;

	int max_ps = -1;

	int ret;



	/*
@@ -1357,6 +1359,7 @@ static void nvme_configure_apst(struct nvme_ctrl *ctrl) 
	if (ctrl->ps_max_latency_us == 0) {

		/* Turn off APST. */

		apste = 0;

		dev_dbg(ctrl->device, "APST disabled\n");

	} else {

		__le64 target = cpu_to_le64(0);

		int state;
@@ -1406,9 +1409,22 @@ static void nvme_configure_apst(struct nvme_ctrl *ctrl) 


			target = cpu_to_le64((state << 3) |

					     (transition_ms << 8));



			if (max_ps == -1)

				max_ps = state;



			if (total_latency_us > max_lat_us)

				max_lat_us = total_latency_us;

		}



		apste = 1;



		if (max_ps == -1) {

			dev_dbg(ctrl->device, "APST enabled but no non-operational states are available\n");

		} else {

			dev_dbg(ctrl->device, "APST enabled: max PS = %d, max round-trip latency = %lluus, table = %*phN\n",

				max_ps, max_lat_us, (int)sizeof(*table), table);

		}

	}



	ret = nvme_set_features(ctrl, NVME_FEAT_AUTO_PST, apste,

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