[Intel-gfx] [PATCH v2 07/11] drm/i915: CRT pixel clock check

[Mika Kahola]

It is possible the we request to have a mode that has
higher pixel clock than our HW can support. This patch
checks if requested pixel clock is lower than the one
supported by the HW. The requested mode is discarded
if we cannot support the requested pixel clock.

This patch applies to CRT.

V2:
- removed computation for max pixel clock

Signed-off-by: Mika Kahola <mika.kahola at intel.com>
---
 drivers/gpu/drm/i915/intel_crt.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_crt.c b/drivers/gpu/drm/i915/intel_crt.c
index 5d78c1f..6e29bce 100644
--- a/drivers/gpu/drm/i915/intel_crt.c
+++ b/drivers/gpu/drm/i915/intel_crt.c
@@ -290,8 +290,10 @@ intel_crt_mode_valid(struct drm_connector *connector,
 		     struct drm_display_mode *mode)
 {
 	struct drm_device *dev = connector->dev;
-
+	struct drm_i915_private *dev_priv = to_i915(dev);
 	int max_clock = 0;
+	int max_pixclk = dev_priv->max_dotclk;
+
 	if (mode->flags & DRM_MODE_FLAG_DBLSCAN)
 		return MODE_NO_DBLESCAN;
 
@@ -305,6 +307,9 @@ intel_crt_mode_valid(struct drm_connector *connector,
 	if (mode->clock > max_clock)
 		return MODE_CLOCK_HIGH;
 
+	if (mode->clock > max_pixclk)
+		return MODE_CLOCK_HIGH;
+
 	/* The FDI receiver on LPT only supports 8bpc and only has 2 lanes. */
 	if (HAS_PCH_LPT(dev) &&
 	    (ironlake_get_lanes_required(mode->clock, 270000, 24) > 2))
-- 
1.9.1