[Intel-gfx] [PATCH v3 10/11] drm/i915: DVO 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 DVO.

V2:
- removed computation for max pixel clock

V3:
- cleanup by removing unnecessary lines

Signed-off-by: Mika Kahola <mika.kahola at intel.com>
---
 drivers/gpu/drm/i915/intel_dvo.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_dvo.c b/drivers/gpu/drm/i915/intel_dvo.c
index fd5e522..2bfc51c 100644
--- a/drivers/gpu/drm/i915/intel_dvo.c
+++ b/drivers/gpu/drm/i915/intel_dvo.c
@@ -247,6 +247,7 @@ intel_dvo_mode_valid(struct drm_connector *connector,
 		     struct drm_display_mode *mode)
 {
 	struct intel_dvo *intel_dvo = intel_attached_dvo(connector);
+	int max_pixclk = to_i915(connector->dev)->max_dotclk;
 
 	if (mode->flags & DRM_MODE_FLAG_DBLSCAN)
 		return MODE_NO_DBLESCAN;
@@ -260,6 +261,9 @@ intel_dvo_mode_valid(struct drm_connector *connector,
 			return MODE_PANEL;
 	}
 
+	if (mode->clock > max_pixclk)
+		return MODE_CLOCK_HIGH;
+
 	return intel_dvo->dev.dev_ops->mode_valid(&intel_dvo->dev, mode);
 }
 
-- 
1.9.1