From c7ad381078ee1b5ce2ab5274bd5f12fee6e1e59a Mon Sep 17 00:00:00 2001 From: Jesse Barnes Date: Thu, 7 Jul 2011 11:11:03 -0700 Subject: [PATCH] drm/i915/dp: manage sink power state if possible On sinks with a DPCD rev of 1.1 or greater, we can send sink power management commands to address 0x600 per section 5.1.5 of the DisplayPort 1.1a spec. Signed-off-by: Jesse Barnes Reviewed-by: Keith Packard Signed-off-by: Keith Packard --- drivers/gpu/drm/i915/intel_dp.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index bca48b0..e2aced6 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -942,11 +942,44 @@ static void ironlake_edp_pll_off(struct drm_encoder *encoder) udelay(200); } +/* If the sink supports it, try to set the power state appropriately */ +static void intel_dp_sink_dpms(struct intel_dp *intel_dp, int mode) +{ + int ret, i; + + /* Should have a valid DPCD by this point */ + if (intel_dp->dpcd[DP_DPCD_REV] < 0x11) + return; + + if (mode != DRM_MODE_DPMS_ON) { + ret = intel_dp_aux_native_write_1(intel_dp, DP_SET_POWER, + DP_SET_POWER_D3); + if (ret != 1) + DRM_DEBUG_DRIVER("failed to write sink power state\n"); + } else { + /* + * When turning on, we need to retry for 1ms to give the sink + * time to wake up. + */ + for (i = 0; i < 3; i++) { + ret = intel_dp_aux_native_write_1(intel_dp, + DP_SET_POWER, + DP_SET_POWER_D0); + if (ret == 1) + break; + msleep(1); + } + } +} + static void intel_dp_prepare(struct drm_encoder *encoder) { struct intel_dp *intel_dp = enc_to_intel_dp(encoder); struct drm_device *dev = encoder->dev; + /* Wake up the sink first */ + intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON); + if (is_edp(intel_dp)) { ironlake_edp_backlight_off(dev); ironlake_edp_panel_off(dev); @@ -990,6 +1023,7 @@ intel_dp_dpms(struct drm_encoder *encoder, int mode) if (mode != DRM_MODE_DPMS_ON) { if (is_edp(intel_dp)) ironlake_edp_backlight_off(dev); + intel_dp_sink_dpms(intel_dp, mode); intel_dp_link_down(intel_dp); if (is_edp(intel_dp)) ironlake_edp_panel_off(dev); @@ -998,6 +1032,7 @@ intel_dp_dpms(struct drm_encoder *encoder, int mode) } else { if (is_edp(intel_dp)) ironlake_edp_panel_vdd_on(intel_dp); + intel_dp_sink_dpms(intel_dp, mode); if (!(dp_reg & DP_PORT_EN)) { intel_dp_start_link_train(intel_dp); if (is_edp(intel_dp)) { -- 2.7.4