Patch "drm/amdkfd: Fix SDMA oversubsription handling" has been added to the 4.4-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    drm/amdkfd: Fix SDMA oversubsription handling

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-amdkfd-fix-sdma-oversubsription-handling.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Thu Feb  1 14:14:46 CET 2018
From: Felix Kuehling <Felix.Kuehling@amd.com>
Date: Wed, 1 Nov 2017 19:21:57 -0400
Subject: drm/amdkfd: Fix SDMA oversubsription handling

From: Felix Kuehling <Felix.Kuehling@amd.com>


[ Upstream commit 8c946b8988acec785bcf67088b6bd0747f36d2d3 ]

SDMA only supports a fixed number of queues. HWS cannot handle
oversubscription.

Signed-off-by: shaoyun liu <shaoyun.liu@amd.com>
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c |   18 +++++++++++++++++
 1 file changed, 18 insertions(+)

--- a/drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c
@@ -205,6 +205,24 @@ int pqm_create_queue(struct process_queu
 
 	switch (type) {
 	case KFD_QUEUE_TYPE_SDMA:
+		if (dev->dqm->queue_count >=
+			CIK_SDMA_QUEUES_PER_ENGINE * CIK_SDMA_ENGINE_NUM) {
+			pr_err("Over-subscription is not allowed for SDMA.\n");
+			retval = -EPERM;
+			goto err_create_queue;
+		}
+
+		retval = create_cp_queue(pqm, dev, &q, properties, f, *qid);
+		if (retval != 0)
+			goto err_create_queue;
+		pqn->q = q;
+		pqn->kq = NULL;
+		retval = dev->dqm->ops.create_queue(dev->dqm, q, &pdd->qpd,
+						&q->properties.vmid);
+		pr_debug("DQM returned %d for create_queue\n", retval);
+		print_queue(q);
+		break;
+
 	case KFD_QUEUE_TYPE_COMPUTE:
 		/* check if there is over subscription */
 		if ((sched_policy == KFD_SCHED_POLICY_HWS_NO_OVERSUBSCRIPTION) &&


Patches currently in stable-queue which might be from Felix.Kuehling@amd.com are

queue-4.4/drm-amdkfd-fix-sdma-oversubsription-handling.patch
queue-4.4/drm-amdkfd-fix-sdma-ring-buffer-size-calculation.patch
queue-4.4/drm-amdgpu-fix-sdma-load-unload-sequence-on-hws-disabled-mode.patch