[Intel-gfx] [PATCH 07/11] drm/i915: Warn if there's a cdclk change in progess

[ville.syrjala at linux.intel.com]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

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 at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_display.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 29dddec..601e97e 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -5234,6 +5234,10 @@ 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);
 }
 
-- 
1.8.5.5