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 <[email protected]> --- drivers/gpu/drm/i915/i915_reg.h | 5 +++++ drivers/gpu/drm/i915/intel_display.c | 4 ++++ 2 files changed, 9 insertions(+), 0 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index 02db299..7377ae4 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -3076,6 +3076,11 @@ #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 b5b15bd..32ffde2 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -7819,6 +7819,7 @@ 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 @@ -7828,6 +7829,9 @@ 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) -- 1.7.4.1 _______________________________________________ Intel-gfx mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/intel-gfx
