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authorAndy Lutomirski <luto@kernel.org>2017-04-21 16:19:23 -0700
committerJens Axboe <axboe@fb.com>2017-04-24 22:03:46 -0600
commitfb0dc3993b537e12ce63511d535ff86efff13c8f (patch)
tree9bbaaa8f5b683dc2a84bfedb1bbb5f92bc9f0c20 /drivers/nvme
parent76e4ad09a30cfb589eb436ad067f4abecb82cc04 (diff)
downloadop-kernel-dev-fb0dc3993b537e12ce63511d535ff86efff13c8f.zip
op-kernel-dev-fb0dc3993b537e12ce63511d535ff86efff13c8f.tar.gz
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: Andy Lutomirski <luto@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'drivers/nvme')
-rw-r--r--drivers/nvme/host/core.c16
1 files changed, 16 insertions, 0 deletions
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 30446e29..3c9547b 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -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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