From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , alan@lxorguk.ukuu.org.uk, Jesse Barnes , "Runyan, Arthur J" , Daniel Vetter , CAI Qian Subject: [ 188/221] drm/i915: disable cpt phase pointer fdi rx workaround Date: Tue, 15 Jan 2013 10:51:55 -0800 Message-Id: <20130115185011.590337962@linuxfoundation.org> In-Reply-To: <20130115184958.025580322@linuxfoundation.org> References: <20130115184958.025580322@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.7-stable review patch. If anyone has any objections, please let me know. ------------------ From: Daniel Vetter 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! Reviewed-by: Jesse Barnes Cc: "Runyan, Arthur J" Cc: stable@vger.kernel.org Signed-off-by: Daniel Vetter Signed-off-by: CAI Qian Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/i915/intel_display.c | 31 ------------------------------- 1 file changed, 31 deletions(-) --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -2302,18 +2302,6 @@ static void intel_fdi_normal_train(struc 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) { @@ -2464,9 +2452,6 @@ static void gen6_fdi_link_train(struct d POSTING_READ(reg); udelay(150); - if (HAS_PCH_CPT(dev)) - cpt_phase_pointer_enable(dev, pipe); - for (i = 0; i < 4; i++) { reg = FDI_TX_CTL(pipe); temp = I915_READ(reg); @@ -2593,9 +2578,6 @@ static void ivb_manual_fdi_link_train(st POSTING_READ(reg); udelay(150); - if (HAS_PCH_CPT(dev)) - cpt_phase_pointer_enable(dev, pipe); - for (i = 0; i < 4; i++) { reg = FDI_TX_CTL(pipe); temp = I915_READ(reg); @@ -2737,17 +2719,6 @@ static void ironlake_fdi_pll_disable(str udelay(100); } -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; @@ -2777,8 +2748,6 @@ static void ironlake_fdi_disable(struct 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 */