| Message ID | 20210110105538.31663-2-chris@chris-wilson.co.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/3] drm/i915/gt: Check for arbitration after writing start seqno | expand |
diff --git a/drivers/gpu/drm/i915/gt/gen8_engine_cs.c b/drivers/gpu/drm/i915/gt/gen8_engine_cs.c index 9a182652a35e..e9ac281644cc 100644 --- a/drivers/gpu/drm/i915/gt/gen8_engine_cs.c +++ b/drivers/gpu/drm/i915/gt/gen8_engine_cs.c @@ -567,6 +567,7 @@ u32 *gen11_emit_fini_breadcrumb_rcs(struct i915_request *rq, u32 *cs) static u32 *gen12_emit_preempt_busywait(struct i915_request *rq, u32 *cs) { + *cs++ = MI_ARB_CHECK; *cs++ = MI_SEMAPHORE_WAIT_TOKEN | MI_SEMAPHORE_GLOBAL_GTT | MI_SEMAPHORE_POLL | @@ -575,7 +576,6 @@ static u32 *gen12_emit_preempt_busywait(struct i915_request *rq, u32 *cs) *cs++ = preempt_address(rq->engine); *cs++ = 0; *cs++ = 0; - *cs++ = MI_NOOP; return cs; }
During igt_reset_nop_engine, it was observed that an unexpected failed engine reset lead to us busywaiting on the stop-ring semaphore (set during the reset preparations) on the first request afterwards. There was no explicit MI_ARB_CHECK in this sequence as the presumption was that the failed MI_SEMAPHORE_WAIT would itself act as an arbitration point. It did not in this circumstance, so force it. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> --- drivers/gpu/drm/i915/gt/gen8_engine_cs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)