linux-kernel - [PATCH 15/15] habanalabs: never fail hard reset of device

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Message-Id: <20190317195927.26238-16-oded.gabbay@gmail.com>
Date:   Sun, 17 Mar 2019 21:59:27 +0200
From:   Oded Gabbay <oded.gabbay@...il.com>
To:     linux-kernel@...r.kernel.org
Cc:     gregkh@...uxfoundation.org
Subject: [PATCH 15/15] habanalabs: never fail hard reset of device

Hard-reset of our device should never fail, due to dangers of permanent
damage to the H/W.

This patch removes the last place in the reset path where the driver might
exit before doing the actual reset.

Signed-off-by: Oded Gabbay <oded.gabbay@...il.com>
---
 drivers/misc/habanalabs/device.c | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/drivers/misc/habanalabs/device.c b/drivers/misc/habanalabs/device.c
index 77d51be66c7e..c51d1062d0bc 100644
--- a/drivers/misc/habanalabs/device.c
+++ b/drivers/misc/habanalabs/device.c
@@ -663,17 +663,9 @@ int hl_device_reset(struct hl_device *hdev, bool hard_reset,
 	/* Go over all the queues, release all CS and their jobs */
 	hl_cs_rollback_all(hdev);
 
-	if (hard_reset) {
-		/* Release kernel context */
-		if (hl_ctx_put(hdev->kernel_ctx) != 1) {
-			dev_err(hdev->dev,
-				"kernel ctx is alive during hard reset\n");
-			rc = -EBUSY;
-			goto out_err;
-		}
-
+	/* Release kernel context */
+	if ((hard_reset) && (hl_ctx_put(hdev->kernel_ctx) == 1))
 		hdev->kernel_ctx = NULL;
-	}
 
 	/* Reset the H/W. It will be in idle state after this returns */
 	hdev->asic_funcs->hw_fini(hdev, hard_reset);
@@ -699,6 +691,13 @@ int hl_device_reset(struct hl_device *hdev, bool hard_reset,
 	if (hard_reset) {
 		hdev->device_cpu_disabled = false;
 
+		if (hdev->kernel_ctx) {
+			dev_crit(hdev->dev,
+				"kernel ctx was alive during hard reset, something is terribly wrong\n");
+			rc = -EBUSY;
+			goto out_err;
+		}
+
 		/* Allocate the kernel context */
 		hdev->kernel_ctx = kzalloc(sizeof(*hdev->kernel_ctx),
 						GFP_KERNEL);
-- 
2.17.1