diff options
Diffstat (limited to '0011-drm-i915-gt-Detect-if-we-miss-WaIdleLiteRestore.patch')
| -rw-r--r-- | 0011-drm-i915-gt-Detect-if-we-miss-WaIdleLiteRestore.patch | 130 |
1 files changed, 0 insertions, 130 deletions
diff --git a/0011-drm-i915-gt-Detect-if-we-miss-WaIdleLiteRestore.patch b/0011-drm-i915-gt-Detect-if-we-miss-WaIdleLiteRestore.patch deleted file mode 100644 index 5ee3f39..0000000 --- a/0011-drm-i915-gt-Detect-if-we-miss-WaIdleLiteRestore.patch +++ /dev/null @@ -1,130 +0,0 @@ -From 8c19c0f7eacb125b9a097d080a385d527f8ff836 Mon Sep 17 00:00:00 2001 -From: Chris Wilson <chris@chris-wilson.co.uk> -Date: Mon, 30 Dec 2019 11:15:30 +0000 -Subject: drm/i915/gt: Detect if we miss WaIdleLiteRestore - -In order to avoid confusing the HW, we must never submit an empty ring -during lite-restore, that is we should always advance the RING_TAIL -before submitting to stay ahead of the RING_HEAD. - -Normally this is prevented by keeping a couple of spare NOPs in the -request->wa_tail so that on resubmission we can advance the tail. This -relies on the request only being resubmitted once, which is the normal -condition as it is seen once for ELSP[1] and then later in ELSP[0]. On -preemption, the requests are unwound and the tail reset back to the -normal end point (as we know the request is incomplete and therefore its -RING_HEAD is even earlier). - -However, if this w/a should fail we would try and resubmit the request -with the RING_TAIL already set to the location of this request's wa_tail -potentially causing a GPU hang. We can spot when we do try and -incorrectly resubmit without advancing the RING_TAIL and spare any -embarrassment by forcing the context restore. - -In the case of preempt-to-busy, we leave the requests running on the HW -while we unwind. As the ring is still live, we cannot rewind our -rq->tail without forcing a reload so leave it set to rq->wa_tail and -only force a reload if we resubmit after a lite-restore. (Normally, the -forced reload will be a part of the preemption event.) - -Fixes: 22b7a426bbe1 ("drm/i915/execlists: Preempt-to-busy") -Closes: https://gitlab.freedesktop.org/drm/intel/issues/673 -Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> -Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com> -Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> -Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> -Cc: stable@vger.kernel.org -Link: https://patchwork.freedesktop.org/patch/msgid/20191209023215.3519970-1-chris@chris-wilson.co.uk -(cherry picked from commit 82c69bf58650e644c61aa2bf5100b63a1070fd2f) ---- - drivers/gpu/drm/i915/gt/intel_lrc.c | 42 ++++++++++++++++++------------------- - 1 file changed, 20 insertions(+), 22 deletions(-) - -diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c -index 06a506c29463..6600b2e08fe3 100644 ---- a/drivers/gpu/drm/i915/gt/intel_lrc.c -+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c -@@ -471,12 +471,6 @@ lrc_descriptor(struct intel_context *ce, struct intel_engine_cs *engine) - return desc; - } - --static void unwind_wa_tail(struct i915_request *rq) --{ -- rq->tail = intel_ring_wrap(rq->ring, rq->wa_tail - WA_TAIL_BYTES); -- assert_ring_tail_valid(rq->ring, rq->tail); --} -- - static struct i915_request * - __unwind_incomplete_requests(struct intel_engine_cs *engine) - { -@@ -495,7 +489,6 @@ __unwind_incomplete_requests(struct intel_engine_cs *engine) - continue; /* XXX */ - - __i915_request_unsubmit(rq); -- unwind_wa_tail(rq); - - /* - * Push the request back into the queue for later resubmission. -@@ -649,13 +642,29 @@ execlists_schedule_out(struct i915_request *rq) - i915_request_put(rq); - } - --static u64 execlists_update_context(const struct i915_request *rq) -+static u64 execlists_update_context(struct i915_request *rq) - { - struct intel_context *ce = rq->hw_context; -- u64 desc; -+ u64 desc = ce->lrc_desc; -+ u32 tail; - -- ce->lrc_reg_state[CTX_RING_TAIL + 1] = -- intel_ring_set_tail(rq->ring, rq->tail); -+ /* -+ * WaIdleLiteRestore:bdw,skl -+ * -+ * We should never submit the context with the same RING_TAIL twice -+ * just in case we submit an empty ring, which confuses the HW. -+ * -+ * We append a couple of NOOPs (gen8_emit_wa_tail) after the end of -+ * the normal request to be able to always advance the RING_TAIL on -+ * subsequent resubmissions (for lite restore). Should that fail us, -+ * and we try and submit the same tail again, force the context -+ * reload. -+ */ -+ tail = intel_ring_set_tail(rq->ring, rq->tail); -+ if (unlikely(ce->lrc_reg_state[CTX_RING_TAIL + 1] == tail)) -+ desc |= CTX_DESC_FORCE_RESTORE; -+ ce->lrc_reg_state[CTX_RING_TAIL + 1] = tail; -+ rq->tail = rq->wa_tail; - - /* - * Make sure the context image is complete before we submit it to HW. -@@ -674,7 +683,6 @@ static u64 execlists_update_context(const struct i915_request *rq) - */ - mb(); - -- desc = ce->lrc_desc; - ce->lrc_desc &= ~CTX_DESC_FORCE_RESTORE; - - return desc; -@@ -1149,16 +1157,6 @@ static void execlists_dequeue(struct intel_engine_cs *engine) - if (!list_is_last(&last->sched.link, - &engine->active.requests)) - return; -- -- /* -- * WaIdleLiteRestore:bdw,skl -- * Apply the wa NOOPs to prevent -- * ring:HEAD == rq:TAIL as we resubmit the -- * request. See gen8_emit_fini_breadcrumb() for -- * where we prepare the padding after the -- * end of the request. -- */ -- last->tail = last->wa_tail; - } - } - --- -cgit v1.2.1-1-g437b - - |