From cd986abbac6044c76b95fd512bc62329ef9959d0 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Fri, 26 Oct 2012 10:58:12 +0200 Subject: [PATCH] drm/i915: Write the FDI RX TU size reg at the right time According to "Graphics BSpec: vol4g North Display Engine Registers [IVB], Display Mode Set Sequence" We need to write the TU size register of the fdi RX unit _before_ starting to train the link. Note: The current code is actually correct as Paulo mentioned in review, but it's a bit confusion since only the fdi rx/tx plls need to be enabled before the cpu pipes/planes. Hence it's still a good idea to move the TU_SIZE setting to the "right" spot in the sequence, to better match Bspec. Reviewed-by: Paulo Zanoni Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/intel_display.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 545e62fa8c77..54b1794c3403 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -2700,9 +2700,6 @@ static void ironlake_fdi_pll_enable(struct intel_crtc *intel_crtc) int pipe = intel_crtc->pipe; u32 reg, temp; - /* Write the TU size bits so error detection works */ - I915_WRITE(FDI_RX_TUSIZE1(pipe), - I915_READ(PIPE_DATA_M1(pipe)) & TU_SIZE_MASK); /* enable PCH FDI RX PLL, wait warmup plus DMI latency */ reg = FDI_RX_CTL(pipe); @@ -3003,6 +3000,11 @@ static void ironlake_pch_enable(struct drm_crtc *crtc) assert_transcoder_disabled(dev_priv, pipe); + /* Write the TU size bits before fdi link training, so that error + * detection works. */ + I915_WRITE(FDI_RX_TUSIZE1(pipe), + I915_READ(PIPE_DATA_M1(pipe)) & TU_SIZE_MASK); + /* For PCH output, training FDI link */ dev_priv->display.fdi_link_train(crtc); -- 2.39.5