This is required for a stable FDI connection. v2: fix and simplify the FDI_RX_MISC bits as noticed by Paulo Zanoni. CC: Paulo Zanoni <paulo.r.zanoni at intel.com> Signed-off-by: Eugeni Dodonov <eugeni.dodonov at intel.com> --- drivers/gpu/drm/i915/i915_reg.h | 3 +++ drivers/gpu/drm/i915/intel_ddi.c | 9 +++++++++ 2 files changed, 12 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index 5b0c5f6..287d277 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -3849,6 +3849,9 @@ #define _FDI_RXA_TUSIZE2 0xf0038 #define _FDI_RXB_TUSIZE1 0xf1030 #define _FDI_RXB_TUSIZE2 0xf1038 +#define FDI_RX_TP1_TO_TP2_48 (2<<20) +#define FDI_RX_TP1_TO_TP2_64 (3<<20) +#define FDI_RX_FDI_DELAY_90 (0x90<<0) #define FDI_RX_MISC(pipe) _PIPE(pipe, _FDI_RXA_MISC, _FDI_RXB_MISC) #define FDI_RX_TUSIZE1(pipe) _PIPE(pipe, _FDI_RXA_TUSIZE1, _FDI_RXB_TUSIZE1) #define FDI_RX_TUSIZE2(pipe) _PIPE(pipe, _FDI_RXA_TUSIZE2, _FDI_RXB_TUSIZE2) diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c index effb263..2d5acd2 100644 --- a/drivers/gpu/drm/i915/intel_ddi.c +++ b/drivers/gpu/drm/i915/intel_ddi.c @@ -170,6 +170,15 @@ void hsw_fdi_link_train(struct drm_crtc *crtc) udelay(600); + /* We need to program FDI_RX_MISC with the default TP1 to TP2 + * values before enabling the receiver, and configure the delay + * for the FDI timing generator to 90h. Luckily, all the other + * bits are supposed to be zeroed, so we can write those values + * directly. + */ + I915_WRITE(FDI_RX_MISC(pipe), FDI_RX_TP1_TO_TP2_48 | + FDI_RX_FDI_DELAY_90); + /* Enable CPU FDI Receiver with auto-training */ reg = FDI_RX_CTL(pipe); I915_WRITE(reg, -- 1.7.11.1
