See bspec, Vol3 Part2, Section 1.1.3 "Display Mode Set Sequence". This applies to all platforms where we currently support eDP on, i.e. ilk, snb & ivb. Without this change we fail to light up the eDP port on previously unused crtcs (likely because something is stuck on the old pipe), and we also fail to properly disable the old pipe (i.e. bit 30 in the PIPECONF register is stuck as set until the next reboot). Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=44001 Signed-Off-by: Daniel Vetter <daniel.vetter at ffwll.ch> --- drivers/gpu/drm/i915/intel_dp.c | 13 ++++++++++--- 1 files changed, 10 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 90b03e9..51053fb 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -1340,16 +1340,23 @@ static void intel_disable_dp(struct intel_encoder *encoder) ironlake_edp_panel_off(intel_dp); intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON); - intel_dp_link_down(intel_dp); - ironlake_edp_panel_vdd_off(intel_dp, false); + + /* cpu edp my only be disable _after_ the cpu pipe/plane is disabled. */ + if (!is_cpu_edp(intel_dp)) { + intel_dp_link_down(intel_dp); + ironlake_edp_panel_vdd_off(intel_dp, false); + } } static void intel_post_disable_dp(struct intel_encoder *encoder) { struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base); - if (is_cpu_edp(intel_dp)) + if (is_cpu_edp(intel_dp)) { + intel_dp_link_down(intel_dp); + ironlake_edp_panel_vdd_off(intel_dp, false); ironlake_edp_pll_off(intel_dp); + } } static void intel_enable_dp(struct intel_encoder *encoder) -- 1.7.7.6
