Attachment 109459 Details for Bug 83677 – Force a CS stall inside gen7 invalidate-caches

[patch] Force a CS stall inside gen7 invalidate-caches

0001-drm-i915-Force-a-CS-stall-inside-gen7-invalidate-cac.patch (text/plain), 1.52 KB, created by Chris Wilson on 2014-11-14 12:14:38 UTC

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Creator: Chris Wilson

Created: 2014-11-14 12:14:38 UTC

Size: 1.52 KB

patch

obsolete

>From 4701fad4e66d65ee2f544e8aeafdc0d53a168aa9 Mon Sep 17 00:00:00 2001
>From: Chris Wilson <chris@chris-wilson.co.uk>
>Date: Fri, 14 Nov 2014 11:02:41 +0000
>Subject: [PATCH] drm/i915: Force a CS stall inside gen7 invalidate-caches
>
>We use the invalidate-caches flush prior to doing a context switch and
>so we rely on it being a command barrier. Frob the CS_STALL bit inside
>the invalidate to make it a full barier before the context switch.
>
>In the requests branch that started the hunt, this done as an explicit
>engine->flush(COMMAND_BARRIER) before the MI_SET_CONTEXT.
>
>Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=83677
>Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
>Cc: stable@vger.kernel.org
>---
> drivers/gpu/drm/i915/intel_ringbuffer.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
>diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
>index ae09258..dbe99fa 100644
>--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
>+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
>@@ -368,6 +368,13 @@ gen7_render_ring_flush(struct intel_engine_cs *ring,
> 		flags |= PIPE_CONTROL_QW_WRITE;
> 		flags |= PIPE_CONTROL_GLOBAL_GTT_IVB;
> 
>+		/*
>+		 * We are also used as barrier before a MI_SET_CONTEXT.
>+		 * Make sure we do a fall pipeline stall before the implied
>+		 * LRI of render state.
>+		 */
>+		flags |= PIPE_CONTROL_STALL_AT_SCOREBOARD;
>+
> 		/* Workaround: we must issue a pipe_control with CS-stall bit
> 		 * set before a pipe_control command that has the state cache
> 		 * invalidate bit set. */
>-- 
>1.9.1
>

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Attachments on bug 83677: 105992 | 106501 | 106508 | 106519 | 106669 | 107665 | 108029 | 108310 | 108459 | 108976 | 109009 | 109018 | 109019 | 109165 | 109331 | 109459 | 110698 | 110699

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