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From:   Breno Leitao <leitao@debian.org>
To:     Keith Busch <kbusch@kernel.org>, Jens Axboe <axboe@kernel.dk>,
        Christoph Hellwig <hch@lst.de>,
        Sagi Grimberg <sagi@grimberg.me>
Cc:     leit@fb.com,
        linux-nvme@lists.infradead.org (open list:NVM EXPRESS DRIVER),
        linux-kernel@vger.kernel.org (open list)
Subject: [PATCH v2] nvme: Print capabilities changes just once
Date:   Thu, 15 Jun 2023 02:49:03 -0700
Message-Id: <20230615094903.1341683-1-leitao@debian.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

This current dev_info() could be very verbose and being printed very
frequently depending on some userspace application sending some specific
commands.

Just print this message once and skip it until the controller resets.
Use a controller flag (NVME_CTRL_DIRTY_CAPABILITY) to track if the
capability needs a reset.

Signed-off-by: Breno Leitao <leitao@debian.org>
---
 drivers/nvme/host/core.c | 6 +++++-
 drivers/nvme/host/nvme.h | 1 +
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 76e8f8b4098e..4b7f9edab5e8 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -1125,8 +1125,11 @@ void nvme_passthru_end(struct nvme_ctrl *ctrl, u32 effects,
 		mutex_unlock(&ctrl->scan_lock);
 	}
 	if (effects & NVME_CMD_EFFECTS_CCC) {
-		dev_info(ctrl->device,
+		if (!test_and_set_bit(NVME_CTRL_DIRTY_CAPABILITY,
+				      &ctrl->flags)) {
+			dev_info(ctrl->device,
 "controller capabilities changed, reset may be required to take effect.\n");
+		}
 	}
 	if (effects & (NVME_CMD_EFFECTS_NIC | NVME_CMD_EFFECTS_NCC)) {
 		nvme_queue_scan(ctrl);
@@ -3280,6 +3283,7 @@ int nvme_init_ctrl_finish(struct nvme_ctrl *ctrl, bool was_suspended)
 			return ret;
 	}
 
+	clear_bit(NVME_CTRL_DIRTY_CAPABILITY, &ctrl->flags);
 	ctrl->identified = true;
 
 	return 0;
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 78308f15e090..f3182134487a 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -243,6 +243,7 @@ enum nvme_ctrl_flags {
 	NVME_CTRL_STARTED_ONCE		= 2,
 	NVME_CTRL_STOPPED		= 3,
 	NVME_CTRL_SKIP_ID_CNS_CS	= 4,
+	NVME_CTRL_DIRTY_CAPABILITY	= 5,
 };
 
 struct nvme_ctrl {
-- 
2.34.1