From: Ville Syrjälä <ville.syrjala@linux.intel.com>
Date: Tue, 26 May 2015 17:22:40 +0000 (+0300)
Subject: drm/i915: Bump CHV PFI credits to 63 when cdclk>=czclk
X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=fcc0008fd02330f1c539a8dd831b00ca9b998cd8;p=deliverable%2Flinux.git

drm/i915: Bump CHV PFI credits to 63 when cdclk>=czclk

Switch from using 31 PFI credits to 63 PFI credits when cdclk>=czclk on
CHV. The spec lists both 31 and 63 as "suggested" values, but based on
feedback from hardware folks we should actually be using 63. Originally
I picked the 31 basically by flipping a coin.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Clint Taylor <Clinton.A.Taylor@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index c4ccc376ae44..193ba79e5a41 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -6055,7 +6055,7 @@ static void vlv_program_pfi_credits(struct drm_i915_private *dev_priv)
 	if (DIV_ROUND_CLOSEST(dev_priv->cdclk_freq, 1000) >= dev_priv->rps.cz_freq) {
 		/* CHV suggested value is 31 or 63 */
 		if (IS_CHERRYVIEW(dev_priv))
-			credits = PFI_CREDIT_31;
+			credits = PFI_CREDIT_63;
 		else
 			credits = PFI_CREDIT(15);
 	} else {