diff mbox

[2/4] drm/i915: set min delay to rpe delay (Efficient frequency) for better performace.

Message ID 1386492406-24716-3-git-send-email-deepak.s@intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

deepak.s@intel.com Dec. 8, 2013, 8:46 a.m. UTC 
From: Deepak S <deepak.s@intel.com>

We use RPe here since it should match the Vmin we were shooting for.
That should give us better perf than if we used the min freq available.
System thermal can take the system to lowest possible freq (RP1). We are
making sure, we calmp the freq to min_delay (RPe).

Signed-off-by: Deepak S <deepak.s@intel.com>
---
 drivers/gpu/drm/i915/intel_pm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Chris Wilson Dec. 8, 2013, 4:07 p.m. UTC | #1 
On Sun, Dec 08, 2013 at 02:16:44PM +0530, deepak.s@intel.com wrote:
> From: Deepak S <deepak.s@intel.com>
> 
> We use RPe here since it should match the Vmin we were shooting for.
> That should give us better perf than if we used the min freq available.
> System thermal can take the system to lowest possible freq (RP1). We are
> making sure, we calmp the freq to min_delay (RPe).

Your perf arguments are fallacious.
-Chris
deepak.s@intel.com Dec. 9, 2013, 1:58 p.m. UTC | #2 
Hi Chris,

My understanding is that running at efficient freq (RPe) where RPe is greater than the min freq (RPn) (RPe > RPn), at same Vmin voltage should give us better performance right?. Please correct me if my understand is not right

Thanks
Deepak

-----Original Message-----
From: Chris Wilson [mailto:chris@chris-wilson.co.uk] 
Sent: Sunday, December 8, 2013 9:37 PM
To: S, Deepak
Cc: intel-gfx@lists.freedesktop.org
Subject: Re: [Intel-gfx] [PATCH 2/4] drm/i915: set min delay to rpe delay (Efficient frequency) for better performace.

On Sun, Dec 08, 2013 at 02:16:44PM +0530, deepak.s@intel.com wrote:
> From: Deepak S <deepak.s@intel.com>
> 
> We use RPe here since it should match the Vmin we were shooting for.
> That should give us better perf than if we used the min freq available.
> System thermal can take the system to lowest possible freq (RP1). We 
> are making sure, we calmp the freq to min_delay (RPe).

Your perf arguments are fallacious.
-Chris

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

Patch

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 7f6c747..716ca24 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -4177,7 +4177,7 @@  static void valleyview_enable_rps(struct drm_device *dev)
 			 vlv_gpu_freq(dev_priv, dev_priv->rps.rpe_delay),
 			 dev_priv->rps.rpe_delay);
 
-	dev_priv->rps.min_delay = valleyview_rps_min_freq(dev_priv);
+	dev_priv->rps.min_delay = dev_priv->rps.rpe_delay;
 	DRM_DEBUG_DRIVER("min GPU freq: %d MHz (%u)\n",
 			 vlv_gpu_freq(dev_priv, dev_priv->rps.min_delay),
 			 dev_priv->rps.min_delay);