From 37ca8d4ccd9860df0747aa2ea281a3c9c4bf8826 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Fri, 30 Oct 2015 19:20:27 +0200 Subject: [PATCH] drm/i915: Enable PCH FIFO underruns later on ILK/SNB/IVB MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit We get spurious PCH FIFO underruns if we enable the reporting too soon after enabling the crtc. Move it to be the last step, after the encoder enable. Additionally we need an extra vblank wait, otherwise we still get the underruns. Presumably the pipe/fdi isn't yet fully up and running otherwise. For symmetry, disable the PCH underrun reporting as the first thing, just before encoder disable, when shutting down the crtc. v2: Do the PCH underrun enable unconditionally (Jani, Daniel) Signed-off-by: Ville Syrjälä Reviewed-by: Jesse Barnes (v1) Link: http://patchwork.freedesktop.org/patch/msgid/1446225627-10809-1-git-send-email-ville.syrjala@linux.intel.com --- drivers/gpu/drm/i915/intel_display.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index a2d5938a9367..c0b6a2428048 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -4840,7 +4840,6 @@ static void ironlake_crtc_enable(struct drm_crtc *crtc) intel_crtc->active = true; intel_set_cpu_fifo_underrun_reporting(dev_priv, pipe, true); - intel_set_pch_fifo_underrun_reporting(dev_priv, pipe, true); for_each_encoder_on_crtc(dev, crtc, encoder) if (encoder->pre_enable) @@ -4878,6 +4877,11 @@ static void ironlake_crtc_enable(struct drm_crtc *crtc) if (HAS_PCH_CPT(dev)) cpt_verify_modeset(dev, intel_crtc->pipe); + + /* Must wait for vblank to avoid spurious PCH FIFO underruns */ + if (intel_crtc->config->has_pch_encoder) + intel_wait_for_vblank(dev, pipe); + intel_set_pch_fifo_underrun_reporting(dev_priv, pipe, true); } /* IPS only exists on ULT machines and is tied to pipe A. */ @@ -5006,15 +5010,15 @@ static void ironlake_crtc_disable(struct drm_crtc *crtc) int pipe = intel_crtc->pipe; u32 reg, temp; + if (intel_crtc->config->has_pch_encoder) + intel_set_pch_fifo_underrun_reporting(dev_priv, pipe, false); + for_each_encoder_on_crtc(dev, crtc, encoder) encoder->disable(encoder); drm_crtc_vblank_off(crtc); assert_vblank_disabled(crtc); - if (intel_crtc->config->has_pch_encoder) - intel_set_pch_fifo_underrun_reporting(dev_priv, pipe, false); - intel_disable_pipe(intel_crtc); ironlake_pfit_disable(intel_crtc, false); -- 2.20.1