Call sequence of double call:
pvr_context_destroy
  pvr_context_kill_queues
    pvr_queue_kill
      drm_sched_entity_destroy
        drm_sched_entity_fini // here
  pvr_context_put
    kref_put(..., pvr_context_release)
      pvr_context_destroy_queues
        pvr_queue_destroy
          drm_sched_entity_fini // here

Call to drm_sched_entity_destroy() from pvr_context_kill_queues() calls
drm_sched_entity_flush() + drm_sched_entity_fini().
drm_sched_entity_flush() ensures all pending jobs are completed and
drm_sched_entity_fini() ensures no further submission is allowed as
per expectation from pvr_context_kill_queues(). Drop the extra
call to drm_sched_entity_fini().

Stack trace for issue with addition of refcounting for DRM entity
stats in commit fd177135f0e6 ("drm/sched: Account entity GPU time"):
[  789.490527] ------------[ cut here ]------------
[  789.490559] refcount_t: underflow; use-after-free.
[  789.490657] WARNING: lib/refcount.c:28 at refcount_warn_saturate+0xf4/0x144, 
CPU#0: kworker/u16:1/440
[  789.490695] Modules linked in: powervr drm_gpuvm drm_exec gpu_sched 
drm_shmem_helper xhci_plat_hcd xhci_hcd dwc3 usbcore usb_common 
snd_soc_simple_card snd_soc_simple_card_utils sa2ul sha512 sha256 dwc3_am62 
sha1 authenc rti_wdt libsha512 at24 sch_fq_codel fuse dm_mod ipv6
[  789.490798] CPU: 0 UID: 0 PID: 440 Comm: kworker/u16:1 Not tainted 
7.0.0-rc7-02049-g5e2c0700091b #22 PREEMPT
[  789.490809] Hardware name: Texas Instruments AM625 SK (DT)
[  789.490815] Workqueue: powervr-sched pvr_queue_fence_release_work [powervr]
[  789.490868] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[  789.490876] pc : refcount_warn_saturate+0xf4/0x144
[  789.490884] lr : refcount_warn_saturate+0xf4/0x144
[  789.490892] sp : ffff8000822cbcc0
[  789.490895] x29: ffff8000822cbcc0 x28: 0000000000000000 x27: 0000000000000000
[  789.490909] x26: 0000000000000000 x25: ffff800081b1e338 x24: ffff000004541405
[  789.490922] x23: ffff000004bea950 x22: ffff00000042e400 x21: ffff000007123e30
[  789.490935] x20: ffff000007123000 x19: ffff000007a80d50 x18: fffffffffffe7768
[  789.490948] x17: 74736574202c6e6f x16: 697461746e656d65 x15: ffff800081b269f0
[  789.490962] x14: 0000000000000030 x13: ffff800081b26a70 x12: 0000000000000211
[  789.490975] x11: 00000000000000c0 x10: 0000000000000b50 x9 : ffff8000822cbb30
[  789.490988] x8 : ffff0000014e7bb0 x7 : ffff00007725e780 x6 : 0000000372a05f49
[  789.491001] x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000010
[  789.491013] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff0000014e7000
[  789.491027] Call trace:
[  789.491032]  refcount_warn_saturate+0xf4/0x144 (P)
[  789.491043]  drm_sched_entity_fini+0x164/0x18c [gpu_sched]
[  789.491081]  pvr_queue_destroy+0x64/0x134 [powervr]
[  789.491110]  pvr_context_destroy_queues+0x34/0x64 [powervr]
[  789.491138]  pvr_context_release+0x70/0xac [powervr]
[  789.491166]  pvr_context_put.part.0+0x5c/0x7c [powervr]
[  789.491193]  pvr_context_put+0x14/0x24 [powervr]
[  789.491221]  pvr_queue_fence_release_work+0x20/0x38 [powervr]
[  789.491249]  process_one_work+0x160/0x4c4
[  789.491264]  worker_thread+0x188/0x310
[  789.491276]  kthread+0x130/0x13c
[  789.491287]  ret_from_fork+0x10/0x20
[  789.491300] ---[ end trace 0000000000000000 ]---

Signed-off-by: Brajesh Gupta <[email protected]>
Fixes: eaf01ee5ba28 ("drm/imagination: Implement job submission and scheduling")
References: fd177135f0e6 ("drm/sched: Account entity GPU time")
---
Changes in v3:
- Fixed a typo.
- Handled missing memory leak for RENDER_CONTEXT.
- Link to v2: 
https://lore.kernel.org/r/[email protected]

Changes in v2:
- Fixed memory leak identified in following error path handling of 
pvr_context_create():
- pvr_context_create()
-   ...
-   err_destroy_queues:
-     pvr_context_destroy_queues()
-       pvr_queue_destroy()
- Link to v1: 
https://lore.kernel.org/r/[email protected]
---
 drivers/gpu/drm/imagination/pvr_context.c | 41 +++++++++++++++++++++++++------
 drivers/gpu/drm/imagination/pvr_queue.c   |  4 ---
 2 files changed, 33 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/imagination/pvr_context.c 
b/drivers/gpu/drm/imagination/pvr_context.c
index eba4694400b5..e2e30908dfce 100644
--- a/drivers/gpu/drm/imagination/pvr_context.c
+++ b/drivers/gpu/drm/imagination/pvr_context.c
@@ -161,22 +161,47 @@ ctx_fw_data_init(void *cpu_ptr, void *priv)
 /**
  * pvr_context_destroy_queues() - Destroy all queues attached to a context.
  * @ctx: Context to destroy queues on.
+ * @queue_entity_fini: Corresponding queues of context to be released for
+ *                     failure path in context creation.
  *
  * Should be called when the last reference to a context object is dropped.
  * It releases all resources attached to the queues bound to this context.
  */
-static void pvr_context_destroy_queues(struct pvr_context *ctx)
+static void pvr_context_destroy_queues(struct pvr_context *ctx, bool 
queue_entity_fini)
 {
        switch (ctx->type) {
        case DRM_PVR_CTX_TYPE_RENDER:
-               pvr_queue_destroy(ctx->queues.fragment);
-               pvr_queue_destroy(ctx->queues.geometry);
+               if (ctx->queues.fragment) {
+                       if (queue_entity_fini)
+                               
drm_sched_entity_fini(&ctx->queues.fragment->entity);
+
+                       pvr_queue_destroy(ctx->queues.fragment);
+               }
+
+               if (ctx->queues.geometry) {
+                       if (queue_entity_fini)
+                               
drm_sched_entity_fini(&ctx->queues.geometry->entity);
+
+                       pvr_queue_destroy(ctx->queues.geometry);
+               }
                break;
+
        case DRM_PVR_CTX_TYPE_COMPUTE:
-               pvr_queue_destroy(ctx->queues.compute);
+               if (ctx->queues.compute) {
+                       if (queue_entity_fini)
+                               
drm_sched_entity_fini(&ctx->queues.compute->entity);
+
+                       pvr_queue_destroy(ctx->queues.compute);
+               }
                break;
+
        case DRM_PVR_CTX_TYPE_TRANSFER_FRAG:
-               pvr_queue_destroy(ctx->queues.transfer);
+               if (ctx->queues.transfer) {
+                       if (queue_entity_fini)
+                               
drm_sched_entity_fini(&ctx->queues.transfer->entity);
+
+                       pvr_queue_destroy(ctx->queues.transfer);
+               }
                break;
        }
 }
@@ -240,7 +265,7 @@ static int pvr_context_create_queues(struct pvr_context 
*ctx,
        return -EINVAL;
 
 err_destroy_queues:
-       pvr_context_destroy_queues(ctx);
+       pvr_context_destroy_queues(ctx, true);
        return err;
 }
 
@@ -349,7 +374,7 @@ int pvr_context_create(struct pvr_file *pvr_file, struct 
drm_pvr_ioctl_create_co
        pvr_fw_object_destroy(ctx->fw_obj);
 
 err_destroy_queues:
-       pvr_context_destroy_queues(ctx);
+       pvr_context_destroy_queues(ctx, true);
 
 err_free_ctx_id:
        /*
@@ -384,7 +409,7 @@ pvr_context_release(struct kref *ref_count)
        spin_unlock(&pvr_dev->ctx_list_lock);
 
        xa_erase(&pvr_dev->ctx_ids, ctx->ctx_id);
-       pvr_context_destroy_queues(ctx);
+       pvr_context_destroy_queues(ctx, false);
        pvr_fw_object_destroy(ctx->fw_obj);
        kfree(ctx->data);
        pvr_vm_context_put(ctx->vm_ctx);
diff --git a/drivers/gpu/drm/imagination/pvr_queue.c 
b/drivers/gpu/drm/imagination/pvr_queue.c
index 7ed60e1c1a86..15cd8adc7528 100644
--- a/drivers/gpu/drm/imagination/pvr_queue.c
+++ b/drivers/gpu/drm/imagination/pvr_queue.c
@@ -1445,15 +1445,11 @@ void pvr_queue_kill(struct pvr_queue *queue)
  */
 void pvr_queue_destroy(struct pvr_queue *queue)
 {
-       if (!queue)
-               return;
-
        mutex_lock(&queue->ctx->pvr_dev->queues.lock);
        list_del_init(&queue->node);
        mutex_unlock(&queue->ctx->pvr_dev->queues.lock);
 
        drm_sched_fini(&queue->scheduler);
-       drm_sched_entity_fini(&queue->entity);
 
        if (WARN_ON(queue->last_queued_job_scheduled_fence))
                dma_fence_put(queue->last_queued_job_scheduled_fence);

---
base-commit: 61de054a772a1feda6364931ab1baf9038abf1c8
change-id: 20260610-b4-sched_fix-ac3b920f475b

Best regards,
-- 
Brajesh Gupta <[email protected]>

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