diff options
| -rw-r--r-- | drivers/gpu/drm/i915/gt/gen8_engine_cs.c | 23 |
1 files changed, 17 insertions, 6 deletions
diff --git a/drivers/gpu/drm/i915/gt/gen8_engine_cs.c b/drivers/gpu/drm/i915/gt/gen8_engine_cs.c index 2e36e0a9d8a6..1ed9f572c8a4 100644 --- a/drivers/gpu/drm/i915/gt/gen8_engine_cs.c +++ b/drivers/gpu/drm/i915/gt/gen8_engine_cs.c @@ -361,19 +361,30 @@ int gen8_emit_init_breadcrumb(struct i915_request *rq) if (IS_ERR(cs)) return PTR_ERR(cs); + *cs++ = MI_STORE_DWORD_IMM_GEN4 | MI_USE_GGTT; + *cs++ = hwsp_offset(rq); + *cs++ = 0; + *cs++ = rq->fence.seqno - 1; + /* * Check if we have been preempted before we even get started. * * After this point i915_request_started() reports true, even if * we get preempted and so are no longer running. + * + * i915_request_started() is used during preemption processing + * to decide if the request is currently inside the user payload + * or spinning on a kernel semaphore (or earlier). For no-preemption + * requests, we do allow preemption on the semaphore before the user + * payload, but do not allow preemption once the request is started. + * + * i915_request_started() is similarly used during GPU hangs to + * determine if the user's payload was guilty, and if so, the + * request is banned. Before the request is started, it is assumed + * to be unharmed and an innocent victim of another's hang. */ - *cs++ = MI_ARB_CHECK; *cs++ = MI_NOOP; - - *cs++ = MI_STORE_DWORD_IMM_GEN4 | MI_USE_GGTT; - *cs++ = hwsp_offset(rq); - *cs++ = 0; - *cs++ = rq->fence.seqno - 1; + *cs++ = MI_ARB_CHECK; intel_ring_advance(rq, cs); |