From da0ef77e1e0ccff703efee82406c629d5c4f4bbb Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Mon, 25 Nov 2019 11:25:20 +0000 Subject: [PATCH] drm/i915/execlists: Fixup cancel_port_requests() I rushed a last minute correction to cancel_port_requests() to prevent the snooping of *execlists->active as the inflight array was being updated, without noticing we iterated the inflight array starting from active! Oops. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=112387 Fixes: 331bf9059157 ("drm/i915/gt: Mark the execlists->active as the primary volatile access") Signed-off-by: Chris Wilson Cc: Mika Kuoppala Reviewed-by: Tvrtko Ursulin Reviewed-by: Andi Shyti Link: https://patchwork.freedesktop.org/patch/msgid/20191125112520.1760492-1-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/gt/intel_lrc.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c index e533ff7ba334..6090357a00fa 100644 --- a/drivers/gpu/drm/i915/gt/intel_lrc.c +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c @@ -2007,19 +2007,17 @@ skip_submit: static void cancel_port_requests(struct intel_engine_execlists * const execlists) { - struct i915_request * const *port, *rq; + struct i915_request * const *port; - for (port = execlists->pending; (rq = *port); port++) - execlists_schedule_out(rq); + for (port = execlists->pending; *port; port++) + execlists_schedule_out(*port); memset(execlists->pending, 0, sizeof(execlists->pending)); /* Mark the end of active before we overwrite *active */ - WRITE_ONCE(execlists->active, execlists->pending); - - for (port = execlists->active; (rq = *port); port++) - execlists_schedule_out(rq); - execlists->active = - memset(execlists->inflight, 0, sizeof(execlists->inflight)); + for (port = xchg(&execlists->active, execlists->pending); *port; port++) + execlists_schedule_out(*port); + WRITE_ONCE(execlists->active, + memset(execlists->inflight, 0, sizeof(execlists->inflight))); } static inline void -- 2.30.2