From: Mika Kuoppala <mika.kuoppala@linux.intel.com>
To: intel-gfx@lists.freedesktop.org
Subject: [PATCH 3/6] drm/i915: Don't emit semaphore wait if wrap happened
Date: Tue, 4 Dec 2012 15:12:02 +0200 [thread overview]
Message-ID: <1354626725-8521-4-git-send-email-mika.kuoppala@intel.com> (raw)
In-Reply-To: <1354626725-8521-1-git-send-email-mika.kuoppala@intel.com>
If wrap just happened we need to prevent emitting waits for
pre wrap values. Detect this and emit no-ops instead.
v2: Use olr > seqno to detect wrap instead of *seqno == 0
as suggested by Chris Wilson.
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
---
drivers/gpu/drm/i915/intel_ringbuffer.c | 21 ++++++++++++++++-----
1 file changed, 16 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 36e1e13a..2305af5 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -626,11 +626,22 @@ gen6_ring_sync(struct intel_ring_buffer *waiter,
if (ret)
return ret;
- intel_ring_emit(waiter,
- dw1 | signaller->semaphore_register[waiter->id]);
- intel_ring_emit(waiter, seqno);
- intel_ring_emit(waiter, 0);
- intel_ring_emit(waiter, MI_NOOP);
+ BUG_ON(!waiter->outstanding_lazy_request);
+
+ /* If seqno wrap happened, omit the wait with no-ops */
+ if (likely(waiter->outstanding_lazy_request > seqno)) {
+ intel_ring_emit(waiter,
+ dw1 |
+ signaller->semaphore_register[waiter->id]);
+ intel_ring_emit(waiter, seqno);
+ intel_ring_emit(waiter, 0);
+ intel_ring_emit(waiter, MI_NOOP);
+ } else {
+ intel_ring_emit(waiter, MI_NOOP);
+ intel_ring_emit(waiter, MI_NOOP);
+ intel_ring_emit(waiter, MI_NOOP);
+ intel_ring_emit(waiter, MI_NOOP);
+ }
intel_ring_advance(waiter);
return 0;
--
1.7.9.5
next prev parent reply other threads:[~2012-12-04 13:12 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-04 13:11 [PATCH 0/6] ring seqno wrap handling Mika Kuoppala
2012-12-04 13:12 ` [PATCH 1/6] drm/i915: Add debugfs entry to read/write next_seqno Mika Kuoppala
2012-12-04 13:12 ` [PATCH 2/6] drm/i915: Fix debugfs seqno info print to use uint Mika Kuoppala
2012-12-04 13:12 ` Mika Kuoppala [this message]
2012-12-05 20:44 ` [PATCH 3/6] drm/i915: Don't emit semaphore wait if wrap happened Paulo Zanoni
2012-12-06 8:51 ` Daniel Vetter
2012-12-06 11:41 ` Paulo Zanoni
2012-12-06 12:14 ` Daniel Vetter
2012-12-06 12:24 ` Chris Wilson
2012-12-06 14:12 ` [PATCH] Detect wraparound using next-seqno rather than waiter->olr Chris Wilson
2012-12-04 13:12 ` [PATCH 4/6] drm/i915: Split intel_ring_begin Mika Kuoppala
2012-12-04 13:12 ` [PATCH 5/6] drm/i915: Add intel_ring_handle_seqno wrap Mika Kuoppala
2012-12-04 13:12 ` [PATCH 6/6] drm/i915: Set initial seqno value close to wrap boundary Mika Kuoppala
2012-12-04 14:05 ` [PATCH 0/6] ring seqno wrap handling Chris Wilson
2012-12-04 22:03 ` Daniel Vetter
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