From: Daniel Vetter Date: Sun, 12 Aug 2012 20:17:14 +0000 (+0200) Subject: drm/i915: reorder edp disabling to fix ivb MacBook Air X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=35a38556d900b9cb5dfa2529c93944b847f8a8a4;p=linux-beck.git drm/i915: reorder edp disabling to fix ivb MacBook Air eDP is tons of fun. It turns out that at least the new MacBook Air 5,1 model absolutely doesn't like the new force vdd dance we've introduced in commit 6cb49835da0426f69a2931bc2a0a8156344b0e41 Author: Daniel Vetter Date: Sun May 20 17:14:50 2012 +0200 drm/i915: enable vdd when switching off the eDP panel But that patch also tried to fix some neat edp sequence issue with the force_vdd timings. Closer inspection reveals that we've raised force_vdd only to do the aux channel communication dp_sink_dpms. If we move the edp_panel_off below that, we don't need any force_vdd for the disable sequence, which makes the Air happy. Unfortunately the reporter of the original bug that the above commit fixed is travelling, so we can't test whether this regresses things. But my theory is that since we don't check for any power-off -> force_vdd-on delays in edp_panel_vdd_on, this was the actual root-cause of this failure. With that force_vdd dance completely eliminated, I'm hopeful the original bug stays fixed, too. For reference the old bug, which hopefully doesn't get broken by this: https://bugzilla.kernel.org/show_bug.cgi?id=43163 In any case, regression fixers win over plain bugfixes, so this needs to go in asap. v2: The crucial pieces seems to be to clear the force_vdd flag uncoditionally, too, in edp_panel_off. Looks like this is left behind by the firmware somehow. v3: The Apple firmware seems to switch off the panel on it's own, hence we still need to keep force_vdd on, but properly clear it when switching the panel off. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=45671 Tested-by: Roberto Romer Tested-by: Daniel Wagner Tested-by: Keith Packard Cc: stable@vger.kernel.org Cc: Keith Packard Signed-off-by: Daniel Vetter --- diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 0a56b9ab0f58..a6c426afaa7a 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -1174,10 +1174,14 @@ static void ironlake_edp_panel_off(struct intel_dp *intel_dp) WARN(!intel_dp->want_panel_vdd, "Need VDD to turn off panel\n"); pp = ironlake_get_pp_control(dev_priv); - pp &= ~(POWER_TARGET_ON | PANEL_POWER_RESET | EDP_BLC_ENABLE); + /* We need to switch off panel power _and_ force vdd, for otherwise some + * panels get very unhappy and cease to work. */ + pp &= ~(POWER_TARGET_ON | EDP_FORCE_VDD | PANEL_POWER_RESET | EDP_BLC_ENABLE); I915_WRITE(PCH_PP_CONTROL, pp); POSTING_READ(PCH_PP_CONTROL); + intel_dp->want_panel_vdd = false; + ironlake_wait_panel_off(intel_dp); } @@ -1287,11 +1291,9 @@ static void intel_dp_prepare(struct drm_encoder *encoder) * ensure that we have vdd while we switch off the panel. */ ironlake_edp_panel_vdd_on(intel_dp); ironlake_edp_backlight_off(intel_dp); - ironlake_edp_panel_off(intel_dp); - intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON); + ironlake_edp_panel_off(intel_dp); intel_dp_link_down(intel_dp); - ironlake_edp_panel_vdd_off(intel_dp, false); } static void intel_dp_commit(struct drm_encoder *encoder) @@ -1326,11 +1328,9 @@ intel_dp_dpms(struct drm_encoder *encoder, int mode) /* Switching the panel off requires vdd. */ ironlake_edp_panel_vdd_on(intel_dp); ironlake_edp_backlight_off(intel_dp); - ironlake_edp_panel_off(intel_dp); - intel_dp_sink_dpms(intel_dp, mode); + ironlake_edp_panel_off(intel_dp); intel_dp_link_down(intel_dp); - ironlake_edp_panel_vdd_off(intel_dp, false); if (is_cpu_edp(intel_dp)) ironlake_edp_pll_off(encoder);