drm/i915: fixup desired rps frequency computation

In commit

commit 20b46e59dd102665ce7168baa215e5b1ee66b69b
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Thu Jul 26 11:16:14 2012 +0200

    drm/i915: Only set the down rps limit when at the loweset frequency

The computation for the new desired frequency was extracted, but since
the desired frequency was passed-by value, the adjustments didn't
propgate back. Fix this.

Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index d0ce894..5050bb8 100644 (file)
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -2272,13 +2272,13 @@ static void ironlake_disable_drps(struct drm_device *dev)
  * ourselves, instead of doing a rmw cycle (which might result in us clearing
  * all limits and the gpu stuck at whatever frequency it is at atm).
  */
-static u32 gen6_rps_limits(struct drm_i915_private *dev_priv, u8 val)
+static u32 gen6_rps_limits(struct drm_i915_private *dev_priv, u8 *val)
 {
        u32 limits;
 
        limits = 0;
-       if (val >= dev_priv->max_delay)
-               val = dev_priv->max_delay;
+       if (*val >= dev_priv->max_delay)
+               *val = dev_priv->max_delay;
        limits |= dev_priv->max_delay << 24;
 
        /* Only set the down limit when we've reached the lowest level to avoid
@@ -2287,8 +2287,8 @@ static u32 gen6_rps_limits(struct drm_i915_private *dev_priv, u8 val)
         * the hw runs at the minimal clock before selecting the desired
         * frequency, if the down threshold expires in that window we will not
         * receive a down interrupt. */
-       if (val <= dev_priv->min_delay) {
-               val = dev_priv->min_delay;
+       if (*val <= dev_priv->min_delay) {
+               *val = dev_priv->min_delay;
                limits |= dev_priv->min_delay << 16;
        }
 
@@ -2298,7 +2298,7 @@ static u32 gen6_rps_limits(struct drm_i915_private *dev_priv, u8 val)
 void gen6_set_rps(struct drm_device *dev, u8 val)
 {
        struct drm_i915_private *dev_priv = dev->dev_private;
-       u32 limits = gen6_rps_limits(dev_priv, val);
+       u32 limits = gen6_rps_limits(dev_priv, &val);
 
        if (val == dev_priv->cur_delay)
                return;