diff mbox

[2/2] drm/i915: Open-code i915_gpu_idle() for handling seqno wrapping

Message ID 1355140577-6572-2-git-send-email-mika.kuoppala@intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Mika Kuoppala Dec. 10, 2012, 11:56 a.m. UTC 
From: Chris Wilson <chris@chris-wilson.co.uk>

The complication is that during seqno wrapping we must be extremely
careful not to write to any ring as that will require a new seqno, and
so would recurse back into the seqno wrap handler. So we cannot call
i915_gpu_idle() as that does additional work beyond simply retiring the
current set of requests, and instead must do the minimal work ourselves
during seqno wrapping.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
---
 drivers/gpu/drm/i915/i915_gem.c |   12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

Comments

Chris Wilson Dec. 10, 2012, 11:59 a.m. UTC | #1 
On Mon, 10 Dec 2012 13:56:17 +0200, Mika Kuoppala <mika.kuoppala@linux.intel.com> wrote:
> From: Chris Wilson <chris@chris-wilson.co.uk>
> @@ -2032,6 +2032,7 @@ i915_add_request(struct intel_ring_buffer *ring,
>  	}
>  
>  	trace_i915_gem_request_add(ring, request->seqno);
> +	dev_priv->last_seqno = request->seqno;

An unnecessary addition to my patch.
-Chris
Mika Kuoppala Dec. 10, 2012, 2:01 p.m. UTC | #2 
On Mon, 10 Dec 2012 11:59:44 +0000, Chris Wilson <chris@chris-wilson.co.uk> wrote:
> On Mon, 10 Dec 2012 13:56:17 +0200, Mika Kuoppala <mika.kuoppala@linux.intel.com> wrote:
> > From: Chris Wilson <chris@chris-wilson.co.uk>
> > @@ -2032,6 +2032,7 @@ i915_add_request(struct intel_ring_buffer *ring,
> >  	}
> >  
> >  	trace_i915_gem_request_add(ring, request->seqno);
> > +	dev_priv->last_seqno = request->seqno;
> 
> An unnecessary addition to my patch.

Indeed, that cruft got in somehow. Fix sent but msg id was eaten
by bash as it contained '$'

> -Chris
> -- 
> Chris Wilson, Intel Open Source Technology Centre
diff mbox

Patch

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index e414507..e753cfc 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1938,11 +1938,15 @@  i915_gem_handle_seqno_wrap(struct drm_device *dev)
 	if (ret == 0)
 		return ret;
 
-	ret = i915_gpu_idle(dev);
-	if (ret)
-		return ret;
-
+	/* Carefully retire all requests without writing to the rings */
+	for_each_ring(ring, dev_priv, i) {
+		ret = intel_ring_idle(ring);
+		if (ret)
+			return ret;
+	}
 	i915_gem_retire_requests(dev);
+
+	/* Finally reset hw state */
 	for_each_ring(ring, dev_priv, i) {
 		ret = intel_ring_handle_seqno_wrap(ring);
 		if (ret)