From: Jesse Barnes Date: Thu, 7 Oct 2010 23:01:15 +0000 (-0700) Subject: drm/i915: add Ironlake clock gating workaround for FDI link training X-Git-Tag: firefly_0821_release~7613^2~3600^2~14^2~52 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=5b2adf897146edeac6a1e438fb67b5a53dbbdf34;p=firefly-linux-kernel-4.4.55.git drm/i915: add Ironlake clock gating workaround for FDI link training Signed-off-by: Jesse Barnes Signed-off-by: Chris Wilson --- diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index a72335e940f1..5a22887a5381 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -2782,6 +2782,7 @@ #define FDI_RXA_CHICKEN 0xc200c #define FDI_RXB_CHICKEN 0xc2010 #define FDI_RX_PHASE_SYNC_POINTER_ENABLE (1) +#define FDI_RX_CHICKEN(pipe) _PIPE(pipe, FDI_RXA_CHICKEN, FDI_RXB_CHICKEN) /* CPU: FDI_TX */ #define FDI_TXA_CTL 0x60100 diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 349710a8014c..5812fc7c5a0f 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -1714,6 +1714,9 @@ static void ironlake_fdi_link_train(struct drm_crtc *crtc) POSTING_READ(reg); udelay(150); + /* Ironlake workaround, enable clock pointer after FDI enable*/ + I915_WRITE(FDI_RX_CHICKEN(pipe), FDI_RX_PHASE_SYNC_POINTER_ENABLE); + reg = FDI_RX_IIR(pipe); for (tries = 0; tries < 5; tries++) { temp = I915_READ(reg); @@ -2192,6 +2195,11 @@ static void ironlake_crtc_disable(struct drm_crtc *crtc) POSTING_READ(reg); udelay(100); + /* Ironlake workaround, disable clock pointer after downing FDI */ + I915_WRITE(FDI_RX_CHICKEN(pipe), + I915_READ(FDI_RX_CHICKEN(pipe) & + ~FDI_RX_PHASE_SYNC_POINTER_ENABLE)); + /* still set train pattern 1 */ reg = FDI_TX_CTL(pipe); temp = I915_READ(reg);