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authorDavid P <megver83@parabola.nu>2020-02-24 22:25:49 -0300
committerDavid P <megver83@parabola.nu>2020-02-24 22:25:49 -0300
commitfb261dccc26646b9c46e8c2a080b202034aabc0e (patch)
tree89cefe6ad76e99c50356c6e6bcddb3c98a291fa3 /libre/linux-libre-pae/0006-drm-i915-execlists-Always-force-a-context-reload-whe.patch
parentbd22097c9a7814644854982dc80e5c271332902c (diff)
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updpkg: libre/linux-libre-pae 5.5.5-1
Signed-off-by: David P <megver83@parabola.nu>
Diffstat (limited to 'libre/linux-libre-pae/0006-drm-i915-execlists-Always-force-a-context-reload-whe.patch')
-rw-r--r--libre/linux-libre-pae/0006-drm-i915-execlists-Always-force-a-context-reload-whe.patch145
1 files changed, 145 insertions, 0 deletions
diff --git a/libre/linux-libre-pae/0006-drm-i915-execlists-Always-force-a-context-reload-whe.patch b/libre/linux-libre-pae/0006-drm-i915-execlists-Always-force-a-context-reload-whe.patch
new file mode 100644
index 000000000..fda8482df
--- /dev/null
+++ b/libre/linux-libre-pae/0006-drm-i915-execlists-Always-force-a-context-reload-whe.patch
@@ -0,0 +1,145 @@
+From db1660f27f62a515dde34ccb192d7c63acf7fde9 Mon Sep 17 00:00:00 2001
+From: Chris Wilson <chris@chris-wilson.co.uk>
+Date: Fri, 7 Feb 2020 21:14:52 +0000
+Subject: [PATCH 06/13] drm/i915/execlists: Always force a context reload when
+ rewinding RING_TAIL
+
+If we rewind the RING_TAIL on a context, due to a preemption event, we
+must force the context restore for the RING_TAIL update to be properly
+handled. Rather than note which preemption events may cause us to rewind
+the tail, compare the new request's tail with the previously submitted
+RING_TAIL, as it turns out that timeslicing was causing unexpected
+rewinds.
+
+ <idle>-0 0d.s2 1280851190us : __execlists_submission_tasklet: 0000:00:02.0 rcs0: expired last=130:4698, prio=3, hint=3
+ <idle>-0 0d.s2 1280851192us : __i915_request_unsubmit: 0000:00:02.0 rcs0: fence 66:119966, current 119964
+ <idle>-0 0d.s2 1280851195us : __i915_request_unsubmit: 0000:00:02.0 rcs0: fence 130:4698, current 4695
+ <idle>-0 0d.s2 1280851198us : __i915_request_unsubmit: 0000:00:02.0 rcs0: fence 130:4696, current 4695
+^---- Note we unwind 2 requests from the same context
+
+ <idle>-0 0d.s2 1280851208us : __i915_request_submit: 0000:00:02.0 rcs0: fence 130:4696, current 4695
+ <idle>-0 0d.s2 1280851213us : __i915_request_submit: 0000:00:02.0 rcs0: fence 134:1508, current 1506
+^---- But to apply the new timeslice, we have to replay the first request
+ before the new client can start -- the unexpected RING_TAIL rewind
+
+ <idle>-0 0d.s2 1280851219us : trace_ports: 0000:00:02.0 rcs0: submit { 130:4696*, 134:1508 }
+ synmark2-5425 2..s. 1280851239us : process_csb: 0000:00:02.0 rcs0: cs-irq head=5, tail=0
+ synmark2-5425 2..s. 1280851240us : process_csb: 0000:00:02.0 rcs0: csb[0]: status=0x00008002:0x00000000
+^---- Preemption event for the ELSP update; note the lite-restore
+
+ synmark2-5425 2..s. 1280851243us : trace_ports: 0000:00:02.0 rcs0: preempted { 130:4698, 66:119966 }
+ synmark2-5425 2..s. 1280851246us : trace_ports: 0000:00:02.0 rcs0: promote { 130:4696*, 134:1508 }
+ synmark2-5425 2.... 1280851462us : __i915_request_commit: 0000:00:02.0 rcs0: fence 130:4700, current 4695
+ synmark2-5425 2.... 1280852111us : __i915_request_commit: 0000:00:02.0 rcs0: fence 130:4702, current 4695
+ synmark2-5425 2.Ns1 1280852296us : process_csb: 0000:00:02.0 rcs0: cs-irq head=0, tail=2
+ synmark2-5425 2.Ns1 1280852297us : process_csb: 0000:00:02.0 rcs0: csb[1]: status=0x00000814:0x00000000
+ synmark2-5425 2.Ns1 1280852299us : trace_ports: 0000:00:02.0 rcs0: completed { 130:4696!, 134:1508 }
+ synmark2-5425 2.Ns1 1280852301us : process_csb: 0000:00:02.0 rcs0: csb[2]: status=0x00000818:0x00000040
+ synmark2-5425 2.Ns1 1280852302us : trace_ports: 0000:00:02.0 rcs0: completed { 134:1508, 0:0 }
+ synmark2-5425 2.Ns1 1280852313us : process_csb: process_csb:2336 GEM_BUG_ON(!i915_request_completed(*execlists->active) && !reset_in_progress(execlists))
+
+Fixes: 8ee36e048c98 ("drm/i915/execlists: Minimalistic timeslicing")
+Referenecs: 82c69bf58650 ("drm/i915/gt: Detect if we miss WaIdleLiteRestore")
+Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
+Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
+Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
+Cc: <stable@vger.kernel.org> # v5.4+
+Link: https://patchwork.freedesktop.org/patch/msgid/20200207211452.2860634-1-chris@chris-wilson.co.uk
+---
+ drivers/gpu/drm/i915/gt/intel_lrc.c | 18 ++++++++----------
+ drivers/gpu/drm/i915/gt/intel_ring.c | 1 +
+ drivers/gpu/drm/i915/gt/intel_ring.h | 8 ++++++++
+ drivers/gpu/drm/i915/gt/intel_ring_types.h | 1 +
+ 4 files changed, 18 insertions(+), 10 deletions(-)
+
+diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
+index d925a1035c9d..1b4784bfa7e5 100644
+--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
++++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
+@@ -1157,7 +1157,7 @@ static u64 execlists_update_context(struct i915_request *rq)
+ {
+ struct intel_context *ce = rq->hw_context;
+ u64 desc = ce->lrc_desc;
+- u32 tail;
++ u32 tail, prev;
+
+ /*
+ * WaIdleLiteRestore:bdw,skl
+@@ -1170,9 +1170,15 @@ static u64 execlists_update_context(struct i915_request *rq)
+ * subsequent resubmissions (for lite restore). Should that fail us,
+ * and we try and submit the same tail again, force the context
+ * reload.
++ *
++ * If we need to return to a preempted context, we need to skip the
++ * lite-restore and force it to reload the RING_TAIL. Otherwise, the
++ * HW has a tendency to ignore us rewinding the TAIL to the end of
++ * an earlier request.
+ */
+ tail = intel_ring_set_tail(rq->ring, rq->tail);
+- if (unlikely(ce->lrc_reg_state[CTX_RING_TAIL] == tail))
++ prev = ce->lrc_reg_state[CTX_RING_TAIL];
++ if (unlikely(intel_ring_direction(rq->ring, tail, prev) <= 0))
+ desc |= CTX_DESC_FORCE_RESTORE;
+ ce->lrc_reg_state[CTX_RING_TAIL] = tail;
+ rq->tail = rq->wa_tail;
+@@ -1651,14 +1657,6 @@ static void execlists_dequeue(struct intel_engine_cs *engine)
+ */
+ __unwind_incomplete_requests(engine);
+
+- /*
+- * If we need to return to the preempted context, we
+- * need to skip the lite-restore and force it to
+- * reload the RING_TAIL. Otherwise, the HW has a
+- * tendency to ignore us rewinding the TAIL to the
+- * end of an earlier request.
+- */
+- last->hw_context->lrc_desc |= CTX_DESC_FORCE_RESTORE;
+ last = NULL;
+ } else if (need_timeslice(engine, last) &&
+ timer_expired(&engine->execlists.timer)) {
+diff --git a/drivers/gpu/drm/i915/gt/intel_ring.c b/drivers/gpu/drm/i915/gt/intel_ring.c
+index 374b28f13ca0..6ff803f397c4 100644
+--- a/drivers/gpu/drm/i915/gt/intel_ring.c
++++ b/drivers/gpu/drm/i915/gt/intel_ring.c
+@@ -145,6 +145,7 @@ intel_engine_create_ring(struct intel_engine_cs *engine, int size)
+
+ kref_init(&ring->ref);
+ ring->size = size;
++ ring->wrap = BITS_PER_TYPE(ring->size) - ilog2(size);
+
+ /*
+ * Workaround an erratum on the i830 which causes a hang if
+diff --git a/drivers/gpu/drm/i915/gt/intel_ring.h b/drivers/gpu/drm/i915/gt/intel_ring.h
+index ea2839d9e044..5bdce24994aa 100644
+--- a/drivers/gpu/drm/i915/gt/intel_ring.h
++++ b/drivers/gpu/drm/i915/gt/intel_ring.h
+@@ -56,6 +56,14 @@ static inline u32 intel_ring_wrap(const struct intel_ring *ring, u32 pos)
+ return pos & (ring->size - 1);
+ }
+
++static inline int intel_ring_direction(const struct intel_ring *ring,
++ u32 next, u32 prev)
++{
++ typecheck(typeof(ring->size), next);
++ typecheck(typeof(ring->size), prev);
++ return (next - prev) << ring->wrap;
++}
++
+ static inline bool
+ intel_ring_offset_valid(const struct intel_ring *ring,
+ unsigned int pos)
+diff --git a/drivers/gpu/drm/i915/gt/intel_ring_types.h b/drivers/gpu/drm/i915/gt/intel_ring_types.h
+index d9f17f38e0cc..3cd7fec7fd8d 100644
+--- a/drivers/gpu/drm/i915/gt/intel_ring_types.h
++++ b/drivers/gpu/drm/i915/gt/intel_ring_types.h
+@@ -45,6 +45,7 @@ struct intel_ring {
+
+ u32 space;
+ u32 size;
++ u32 wrap;
+ u32 effective_size;
+ };
+
+--
+2.25.1
+