[ 120/173] drm/i915: disable cpt phase pointer fdi rx workaround
From: Ben Hutchings <hidden>
Date: 2012-12-28 19:44:33
Also in:
lkml
3.2-stable review patch. If anyone has any objections, please let me know.
------------------
From: Daniel Vetter <redacted>
commit 539526b4137bc0e7a8806c38c8522f226814a0e6 upstream.
We've originally added this in
commit 291427f5fdadec6e4be2924172e83588880e1539
Author: Jesse Barnes [off-list ref]
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 [off-list ref]
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 [off-list ref]
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" <redacted>
Reviewed-by: Jesse Barnes <redacted>
Signed-off-by: Daniel Vetter <redacted>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <redacted>
---
drivers/gpu/drm/i915/intel_display.c | 29 -----------------------------
1 file changed, 29 deletions(-)
--- 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(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) {
@@ -2544,8 +2532,6 @@ static void gen6_fdi_link_train(struct d 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(st 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(stru } } -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 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 */