From: Daniel Vetter Date: Sat, 8 Dec 2012 11:58:33 +0000 (+0100) Subject: drm/i915: disable cpt phase pointer fdi rx workaround X-Git-Tag: v3.2.36~54 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=3d66fd735d84acb52b09fd5c441e3b206cd226a5;p=karo-tx-linux.git drm/i915: disable cpt phase pointer fdi rx workaround commit 539526b4137bc0e7a8806c38c8522f226814a0e6 upstream. We've originally added this in commit 291427f5fdadec6e4be2924172e83588880e1539 Author: Jesse Barnes Date: Fri Jul 29 12:42:37 2011 -0700 drm/i915: apply phase pointer override on SNB+ too and then copy-pasted it over to ivb/ppt. The w/a was originally added for ilk/ibx in commit 5b2adf897146edeac6a1e438fb67b5a53dbbdf34 Author: Jesse Barnes Date: Thu Oct 7 16:01:15 2010 -0700 drm/i915: add Ironlake clock gating workaround for FDI link training and fixed up a bit in commit 6f06ce184c765fd8d50669a8d12fdd566c920859 Author: Jesse Barnes Date: Tue Jan 4 15:09:38 2011 -0800 drm/i915: set phase sync pointer override enable before setting phase sync pointer It turns out that this w/a isn't actually required on cpt/ppt and positively harmful on ivb/ppt when using fdi B/C links - it results in a black screen occasionally, with seemingfully everything working as it should. The only failure indication I've found in the hw is that eventually (but not right after the modeset completes) a pipe underrun is signalled. Big thanks to Arthur Runyan for all the ideas for registers to check and changes to test, otherwise I couldn't ever have tracked this down! Cc: "Runyan, Arthur J" Reviewed-by: Jesse Barnes Signed-off-by: Daniel Vetter [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings --- diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 5d3b0a5b3200..b53a408426f7 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -2384,18 +2384,6 @@ static void intel_fdi_normal_train(struct drm_crtc *crtc) FDI_FE_ERRC_ENABLE); } -static void cpt_phase_pointer_enable(struct drm_device *dev, int pipe) -{ - struct drm_i915_private *dev_priv = dev->dev_private; - u32 flags = I915_READ(SOUTH_CHICKEN1); - - flags |= FDI_PHASE_SYNC_OVR(pipe); - I915_WRITE(SOUTH_CHICKEN1, flags); /* once to unlock... */ - flags |= FDI_PHASE_SYNC_EN(pipe); - I915_WRITE(SOUTH_CHICKEN1, flags); /* then again to enable */ - POSTING_READ(SOUTH_CHICKEN1); -} - /* The FDI link training functions for ILK/Ibexpeak. */ static void ironlake_fdi_link_train(struct drm_crtc *crtc) { @@ -2544,8 +2532,6 @@ static void gen6_fdi_link_train(struct drm_crtc *crtc) POSTING_READ(reg); udelay(150); - cpt_phase_pointer_enable(dev, pipe); - for (i = 0; i < 4; i++) { reg = FDI_TX_CTL(pipe); temp = I915_READ(reg); @@ -2664,8 +2650,6 @@ static void ivb_manual_fdi_link_train(struct drm_crtc *crtc) POSTING_READ(reg); udelay(150); - cpt_phase_pointer_enable(dev, pipe); - for (i = 0; i < 4; i++) { reg = FDI_TX_CTL(pipe); temp = I915_READ(reg); @@ -2775,17 +2759,6 @@ static void ironlake_fdi_pll_enable(struct drm_crtc *crtc) } } -static void cpt_phase_pointer_disable(struct drm_device *dev, int pipe) -{ - struct drm_i915_private *dev_priv = dev->dev_private; - u32 flags = I915_READ(SOUTH_CHICKEN1); - - flags &= ~(FDI_PHASE_SYNC_EN(pipe)); - I915_WRITE(SOUTH_CHICKEN1, flags); /* once to disable... */ - flags &= ~(FDI_PHASE_SYNC_OVR(pipe)); - I915_WRITE(SOUTH_CHICKEN1, flags); /* then again to lock */ - POSTING_READ(SOUTH_CHICKEN1); -} static void ironlake_fdi_disable(struct drm_crtc *crtc) { struct drm_device *dev = crtc->dev; @@ -2815,8 +2788,6 @@ static void ironlake_fdi_disable(struct drm_crtc *crtc) I915_WRITE(FDI_RX_CHICKEN(pipe), I915_READ(FDI_RX_CHICKEN(pipe) & ~FDI_RX_PHASE_SYNC_POINTER_EN)); - } else if (HAS_PCH_CPT(dev)) { - cpt_phase_pointer_disable(dev, pipe); } /* still set train pattern 1 */