From a20ab592d1a87218229109d109b8e2feae6f598d Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Wed, 21 Aug 2019 15:23:36 +0100 Subject: [PATCH] drm/i915/execlists: Set priority hint prior to submission Since we now run process_csb() outside of the engine->active.lock, we can process a CS-event immediately upon our ELSP write. As we currently inspect the pending queue *after* the ELSP write, there is an opportunity for a CS-event to update the pending queue before we can read it, making ourselves chases an invalid pointer. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=111427 Fixes: df403069029d ("drm/i915/execlists: Lift process_csb() out of the irq-off spinlock") Signed-off-by: Chris Wilson Cc: Mika Kuoppala Reviewed-by: Mika Kuoppala Link: https://patchwork.freedesktop.org/patch/msgid/20190821142336.21609-1-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/gt/intel_lrc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c index 44780e7fafec..d42584439f51 100644 --- a/drivers/gpu/drm/i915/gt/intel_lrc.c +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c @@ -1335,9 +1335,9 @@ static void execlists_dequeue(struct intel_engine_cs *engine) if (submit) { *port = execlists_schedule_in(last, port - execlists->pending); memset(port + 1, 0, (last_port - port) * sizeof(*port)); - execlists_submit_ports(engine); execlists->switch_priority_hint = switch_prio(engine, *execlists->pending); + execlists_submit_ports(engine); } else { ring_set_paused(engine, 0); }