From 23d0b13036d14257ae4d226209cd7845f25af8e0 Mon Sep 17 00:00:00 2001 From: Ben Widawsky Date: Thu, 10 Apr 2014 14:32:41 -0700 Subject: [PATCH] drm/i915/bdw: Add 42ms delay for IPS disable This is a requirement added to the spec. This patch will prevent persistent corruption on the display. v2: Make the wait before the vblank wait. (Art) Try to finish early by polling the register s/present/prevent (Chris) Cc: Art Runyan Signed-off-by: Ben Widawsky [danvet: Upgrade debug output to ERROR.] Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/intel_display.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 51b3603d5ed7..209fbbe64161 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -3583,10 +3583,13 @@ void hsw_disable_ips(struct intel_crtc *crtc) return; assert_plane_enabled(dev_priv, crtc->plane); - if (IS_BROADWELL(crtc->base.dev)) { + if (IS_BROADWELL(dev)) { mutex_lock(&dev_priv->rps.hw_lock); WARN_ON(sandybridge_pcode_write(dev_priv, DISPLAY_IPS_CONTROL, 0)); mutex_unlock(&dev_priv->rps.hw_lock); + /* wait for pcode to finish disabling IPS, which may take up to 42ms */ + if (wait_for((I915_READ(IPS_CTL) & IPS_ENABLE) == 0, 42)) + DRM_ERROR("Timed out waiting for IPS disable\n"); } else { I915_WRITE(IPS_CTL, 0); POSTING_READ(IPS_CTL); -- 2.20.1