| Message ID | 1432917856-12261-23-git-send-email-John.C.Harrison@Intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 29/05/2015 17:43, John.C.Harrison@Intel.com wrote: > From: John Harrison <John.C.Harrison@Intel.com> > > In execlist mode, context initialisation is deferred until first use of the > given context. This is because execlist mode has per ring context state and thus > many more context storage objects than legacy mode and many are never actually > used. Previously, the initialisation commands were written to the ring and > tagged with some random request structure via the OLR. This seemed to be causing > a null pointer deference bug under certain circumstances (BZ:88865). > > This patch adds explicit request creation and submission to the deferred > initialisation code path. Thus removing any reliance on or randomness caused by > the OLR. > > Note that it should be possible to move the deferred context creation until even > later - when the context is actually switched to rather than when it is merely > validated. This would allow the initialisation to be done within the request of > the work that is wanting to use the context. Hence, the extra request that is > created, used and retired just for the context init could be removed completely. > However, this is left for a follow up patch. > > For: VIZ-5115 > Signed-off-by: John Harrison <John.C.Harrison@Intel.com> > --- > drivers/gpu/drm/i915/intel_lrc.c | 11 ++++++++++- > 1 file changed, 10 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c > index 37efa93..2730efd 100644 > --- a/drivers/gpu/drm/i915/intel_lrc.c > +++ b/drivers/gpu/drm/i915/intel_lrc.c > @@ -1971,13 +1971,22 @@ int intel_lr_context_deferred_create(struct intel_context *ctx, > lrc_setup_hardware_status_page(ring, ctx_obj); > else if (ring->id == RCS && !ctx->rcs_initialized) { > if (ring->init_context) { > - ret = ring->init_context(ring, ctx); > + struct drm_i915_gem_request *req; > + > + ret = i915_gem_request_alloc(ring, ctx, &req); > + if (ret) > + return ret; > + > + ret = ring->init_context(req->ring, ctx); > if (ret) { > DRM_ERROR("ring init context: %d\n", ret); > + i915_gem_request_cancel(req); > ctx->engine[ring->id].ringbuf = NULL; > ctx->engine[ring->id].state = NULL; > goto error; > } > + > + i915_add_request_no_flush(req->ring); > } > > ctx->rcs_initialized = true; > Reviewed-by: Tomas Elf <tomas.elf@intel.com> Thanks, Tomas
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c index 37efa93..2730efd 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -1971,13 +1971,22 @@ int intel_lr_context_deferred_create(struct intel_context *ctx, lrc_setup_hardware_status_page(ring, ctx_obj); else if (ring->id == RCS && !ctx->rcs_initialized) { if (ring->init_context) { - ret = ring->init_context(ring, ctx); + struct drm_i915_gem_request *req; + + ret = i915_gem_request_alloc(ring, ctx, &req); + if (ret) + return ret; + + ret = ring->init_context(req->ring, ctx); if (ret) { DRM_ERROR("ring init context: %d\n", ret); + i915_gem_request_cancel(req); ctx->engine[ring->id].ringbuf = NULL; ctx->engine[ring->id].state = NULL; goto error; } + + i915_add_request_no_flush(req->ring); } ctx->rcs_initialized = true;