[Intel-gfx] [PATCH v4 6/6] drm/i915: TV 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 TV.

V2:
- removed computation for max pixel clock

V3:
- cleanup by removing unnecessary lines

V4:
- max_pixclk variable renamed as max_dotclk

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

diff --git a/drivers/gpu/drm/i915/intel_tv.c b/drivers/gpu/drm/i915/intel_tv.c
index 948cbff..eeb4e3c 100644
--- a/drivers/gpu/drm/i915/intel_tv.c
+++ b/drivers/gpu/drm/i915/intel_tv.c
@@ -897,6 +897,10 @@ intel_tv_mode_valid(struct drm_connector *connector,
 {
 	struct intel_tv *intel_tv = intel_attached_tv(connector);
 	const struct tv_mode *tv_mode = intel_tv_mode_find(intel_tv);
+	int max_dotclk = to_i915(connector->dev)->max_dotclk_freq;
+
+	if (mode->clock > max_dotclk)
+		return MODE_CLOCK_HIGH;
 
 	/* Ensure TV refresh is close to desired refresh */
 	if (tv_mode && abs(tv_mode->refresh - drm_mode_vrefresh(mode) * 1000)
-- 
1.9.1