[PATCH 2/4] habanalabs: release kernel context after hw_fini

Oded Gabbay
2020-09-24T07:03:10Z

Some engines use resources that belong to the kernel context (e.g. MMU
mappings). In case the halt-engines doesn't work properly due to H/W
restriction, we need to make sure the kernel context lives on until after
the hw_fini. The hw_fini resets the ASIC after that no engine is alive and
we can safely close the kernel context.

Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
---
drivers/misc/habanalabs/common/device.c | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/drivers/misc/habanalabs/common/device.c b/drivers/misc/habanalabs/common/device.c
index 196e35d71118..20572224099a 100644
--- a/drivers/misc/habanalabs/common/device.c
+++ b/drivers/misc/habanalabs/common/device.c
@@ -967,14 +967,13 @@ int hl_device_reset(struct hl_device *hdev, bool hard_reset,
flush_workqueue(hdev->eq_wq);
}

- /* 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);

if (hard_reset) {
+ /* Release kernel context */
+ if (hl_ctx_put(hdev->kernel_ctx) == 1)
+ hdev->kernel_ctx = NULL;
hl_vm_fini(hdev);
hl_mmu_fini(hdev);
hl_eq_reset(hdev, &hdev->event_queue);
@@ -1465,13 +1464,13 @@ void hl_device_fini(struct hl_device *hdev)

hl_cb_pool_fini(hdev);

+ /* Reset the H/W. It will be in idle state after this returns */
+ hdev->asic_funcs->hw_fini(hdev, true);
+
/* Release kernel context */
if ((hdev->kernel_ctx) && (hl_ctx_put(hdev->kernel_ctx) != 1))
dev_err(hdev->dev, "kernel ctx is still alive\n");

- /* Reset the H/W. It will be in idle state after this returns */
- hdev->asic_funcs->hw_fini(hdev, true);
-
hl_vm_fini(hdev);

hl_mmu_fini(hdev);
--
2.17.1