From: Jesse Barnes Date: Wed, 27 Jul 2011 18:51:40 +0000 (-0700) Subject: drm/i915: apply timing generator bug workaround on CPT and PPT X-Git-Tag: firefly_0821_release~3680^2~4714^2~10^2~8^2~2 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=3bcf603f6d5d18bd9d076dc280de71f48add4101;p=firefly-linux-kernel-4.4.55.git drm/i915: apply timing generator bug workaround on CPT and PPT On CougarPoint and PantherPoint PCH chips, the timing generator may fail to start after DP training completes. This is due to a bug in the FDI autotraining detect logic (which will stall the timing generator and re-enable it once training completes), so disable it to avoid silent DP mode setting failures. Signed-off-by: Jesse Barnes Signed-off-by: Keith Packard --- diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index f7315653a842..00bd51070314 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -3072,6 +3072,11 @@ #define TRANS_6BPC (2<<5) #define TRANS_12BPC (3<<5) +#define _TRANSA_CHICKEN2 0xf0064 +#define _TRANSB_CHICKEN2 0xf1064 +#define TRANS_CHICKEN2(pipe) _PIPE(pipe, _TRANSA_CHICKEN2, _TRANSB_CHICKEN2) +#define TRANS_AUTOTRAIN_GEN_STALL_DIS (1<<31) + #define SOUTH_CHICKEN2 0xc2004 #define DPLS_EDP_PPS_FIX_DIS (1<<0) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index d9b8c15998d9..502efc37b074 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -7524,6 +7524,7 @@ static void ibx_init_clock_gating(struct drm_device *dev) static void cpt_init_clock_gating(struct drm_device *dev) { struct drm_i915_private *dev_priv = dev->dev_private; + int pipe; /* * On Ibex Peak and Cougar Point, we need to disable clock @@ -7533,6 +7534,9 @@ static void cpt_init_clock_gating(struct drm_device *dev) I915_WRITE(SOUTH_DSPCLK_GATE_D, PCH_DPLSUNIT_CLOCK_GATE_DISABLE); I915_WRITE(SOUTH_CHICKEN2, I915_READ(SOUTH_CHICKEN2) | DPLS_EDP_PPS_FIX_DIS); + /* Without this, mode sets may fail silently on FDI */ + for_each_pipe(pipe) + I915_WRITE(TRANS_CHICKEN2(pipe), TRANS_AUTOTRAIN_GEN_STALL_DIS); } static void ironlake_teardown_rc6(struct drm_device *dev)