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From:   Oded Gabbay <oded.gabbay@gmail.com>
To:     linux-kernel@vger.kernel.org, oshpigelman@habana.ai,
        ttayar@habana.ai
Cc:     gregkh@linuxfoundation.org
Subject: [PATCH] habanalabs: add debug print when rejecting CS
Date:   Thu, 18 Jul 2019 09:29:54 +0300
Message-Id: <20190718062954.15283-1-oded.gabbay@gmail.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

When rejecting CS because of too many in-flight CS, print a debug message
about it as it useful to know when the user is debugging (it indicates a
back-pressure from the driver as the device is not fast enough to consume
the CS)

Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
---
 drivers/misc/habanalabs/command_submission.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/misc/habanalabs/command_submission.c b/drivers/misc/habanalabs/command_submission.c
index 6ad83d5ef4b0..f4e2c2ad0057 100644
--- a/drivers/misc/habanalabs/command_submission.c
+++ b/drivers/misc/habanalabs/command_submission.c
@@ -305,6 +305,8 @@ static int allocate_cs(struct hl_device *hdev, struct hl_ctx *ctx,
 	other = ctx->cs_pending[fence->cs_seq & (HL_MAX_PENDING_CS - 1)];
 	if ((other) && (!dma_fence_is_signaled(other))) {
 		spin_unlock(&ctx->cs_lock);
+		dev_dbg(hdev->dev,
+			"Rejecting CS because of too many in-flights CS\n");
 		rc = -EAGAIN;
 		goto free_fence;
 	}
-- 
2.17.1