From 799487f51d7419e33736d81b0b9087b2aaa593af Mon Sep 17 00:00:00 2001 From: Mika Kahola Date: Tue, 2 Feb 2016 15:16:38 +0200 Subject: [PATCH] drm/i915: DisplayPort pixel clock check MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 DisplayPort. V2: - removed computation for max DOT clock V3: - cleanup by removing unnecessary lines V4: - max_pixclk renamed as max_dotclk Signed-off-by: Mika Kahola Reviewed-by: Ville Syrjälä Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/1454419003-6001-2-git-send-email-mika.kahola@intel.com --- drivers/gpu/drm/i915/intel_dp.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index a073f04a5330..65d50847d359 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -203,6 +203,7 @@ intel_dp_mode_valid(struct drm_connector *connector, struct drm_display_mode *fixed_mode = intel_connector->panel.fixed_mode; int target_clock = mode->clock; int max_rate, mode_rate, max_lanes, max_link_clock; + int max_dotclk = to_i915(connector->dev)->max_dotclk_freq; if (is_edp(intel_dp) && fixed_mode) { if (mode->hdisplay > fixed_mode->hdisplay) @@ -220,7 +221,7 @@ intel_dp_mode_valid(struct drm_connector *connector, max_rate = intel_dp_max_data_rate(max_link_clock, max_lanes); mode_rate = intel_dp_link_required(target_clock, 18); - if (mode_rate > max_rate) + if (mode_rate > max_rate || target_clock > max_dotclk) return MODE_CLOCK_HIGH; if (mode->clock < 10000) -- 2.20.1