[Intel-gfx] [PATCH v2 04/11] drm/i915: LVDS pixel clock check

Mika Kahola mika.kahola at intel.com
Wed Jul 29 23:49:31 PDT 2015


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 LVDS.

V2:
- removed computation for max pixel clock

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

diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c
index cb634f4..5648295 100644
--- a/drivers/gpu/drm/i915/intel_lvds.c
+++ b/drivers/gpu/drm/i915/intel_lvds.c
@@ -289,11 +289,15 @@ intel_lvds_mode_valid(struct drm_connector *connector,
 {
 	struct intel_connector *intel_connector = to_intel_connector(connector);
 	struct drm_display_mode *fixed_mode = intel_connector->panel.fixed_mode;
+	struct drm_i915_private *dev_priv = to_i915(connector->dev);
+	int max_pixclk = dev_priv->max_dotclk;
 
 	if (mode->hdisplay > fixed_mode->hdisplay)
 		return MODE_PANEL;
 	if (mode->vdisplay > fixed_mode->vdisplay)
 		return MODE_PANEL;
+	if (mode->clock > max_pixclk)
+		return MODE_CLOCK_HIGH;
 
 	return MODE_OK;
 }
-- 
1.9.1



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