drm/i915: Warn if there's a cdclk change in progess
authorVille Syrjälä <ville.syrjala@linux.intel.com>
Fri, 13 Jun 2014 10:37:53 +0000 (13:37 +0300)
committerDaniel Vetter <daniel.vetter@ffwll.ch>
Mon, 7 Jul 2014 09:25:47 +0000 (11:25 +0200)
If someone is interested in the current cdclk frquency it should
be stable and not in process of changing frquency. Warn if the current
and requested cdclk don't match in .get_display_clock_spee() on vlv.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drivers/gpu/drm/i915/intel_display.c

index 251a095acceb1c03359dd401ad6afb740763a128..ac3ee2cee4b6034c75c070750c05779d1d16c62f 100644 (file)
@@ -5275,6 +5275,10 @@ static int valleyview_get_display_clock_speed(struct drm_device *dev)
 
        divider = val & DISPLAY_FREQUENCY_VALUES;
 
+       WARN((val & DISPLAY_FREQUENCY_STATUS) !=
+            (divider << DISPLAY_FREQUENCY_STATUS_SHIFT),
+            "cdclk change in progress\n");
+
        return DIV_ROUND_CLOSEST(vco << 1, divider + 1);
 }