[PATCH 07/12] drm/i915/gvt: Hold a reference on the request

Chris Wilson
2016-10-19T10:12:02Z

The workload took a pointer to the request, and even waited upon,
without holding a reference on the request. Take that reference
explicitly and fix up the error path following request allocation that
missed flushing the request.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
drivers/gpu/drm/i915/gvt/scheduler.c | 24 +++++++++++++-----------
1 file changed, 13 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/i915/gvt/scheduler.c b/drivers/gpu/drm/i915/gvt/scheduler.c
index b15cdf5978a9..224f19ae61ab 100644
--- a/drivers/gpu/drm/i915/gvt/scheduler.c
+++ b/drivers/gpu/drm/i915/gvt/scheduler.c
@@ -163,6 +163,7 @@ static int dispatch_workload(struct intel_vgpu_workload *workload)
int ring_id = workload->ring_id;
struct i915_gem_context *shadow_ctx = workload->vgpu->shadow_ctx;
struct drm_i915_private *dev_priv = workload->vgpu->gvt->dev_priv;
+ struct drm_i915_gem_request *rq;
int ret;

gvt_dbg_sched("ring id %d prepare to dispatch workload %p\n",
@@ -171,17 +172,16 @@ static int dispatch_workload(struct intel_vgpu_workload *workload)
shadow_ctx->desc_template = workload->ctx_desc.addressing_mode <<
GEN8_CTX_ADDRESSING_MODE_SHIFT;

- workload->req = i915_gem_request_alloc(dev_priv->engine[ring_id],
- shadow_ctx);
- if (IS_ERR_OR_NULL(workload->req)) {
+ rq = i915_gem_request_alloc(dev_priv->engine[ring_id], shadow_ctx);
+ if (IS_ERR(rq)) {
gvt_err("fail to allocate gem request\n");
- workload->status = PTR_ERR(workload->req);
- workload->req = NULL;
+ workload->status = PTR_ERR(rq);
return workload->status;
}

- gvt_dbg_sched("ring id %d get i915 gem request %p\n",
- ring_id, workload->req);
+ gvt_dbg_sched("ring id %d get i915 gem request %p\n", ring_id, rq);
+
+ workload->req = i915_gem_request_get(rq);

mutex_lock(&gvt->lock);

@@ -208,16 +208,16 @@ static int dispatch_workload(struct intel_vgpu_workload *workload)
gvt_dbg_sched("ring id %d submit workload to i915 %p\n",
ring_id, workload->req);

- i915_add_request_no_flush(workload->req);
-
+ i915_add_request_no_flush(rq);
workload->dispatched = true;
return 0;
err:
workload->status = ret;
- if (workload->req)
- workload->req = NULL;
+ i915_gem_request_put(fetch_and_zero(&workload->req));

mutex_unlock(&gvt->lock);
+
+ i915_add_request_no_flush(rq);
return ret;
}

@@ -458,6 +458,8 @@ static int workload_thread(void *priv)

complete_current_workload(gvt, ring_id);

+ i915_gem_request_put(fetch_and_zero(&workload->req));
+
if (need_force_wake)
intel_uncore_forcewake_put(gvt->dev_priv,
FORCEWAKE_ALL);
--
2.9.3