From 6ee8bab09d515503f9f1d01690840c2bd5f66267 Mon Sep 17 00:00:00 2001 From: Eugeni Dodonov Date: Wed, 9 May 2012 20:30:31 -0300 Subject: [PATCH] drm/i915: detect PCH encoders on Haswell On Haswell, the recommended PCH-connected output is the one driven by DDI E in FDI mode, used for VGA connection. All the others are handled by the CPU. Note that this does not accounts for Haswell/PPT combination yet, so if we encounter such combination an error message is thrown to indicate that things could go wrong. v2: improve non-LPT detection warning per Daniel Vetter's suggestion. Signed-off-by: Eugeni Dodonov Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/intel_display.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index cc910e69f709..bb049a178632 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -2610,6 +2610,22 @@ static bool intel_crtc_driving_pch(struct drm_crtc *crtc) if (encoder->base.crtc != crtc) continue; + /* On Haswell, LPT PCH handles the VGA connection via FDI, and Haswell + * CPU handles all others */ + if (IS_HASWELL(dev)) { + /* It is still unclear how this will work on PPT, so throw up a warning */ + WARN_ON(!HAS_PCH_LPT(dev)); + + if (encoder->type == DRM_MODE_ENCODER_DAC) { + DRM_DEBUG_KMS("Haswell detected DAC encoder, assuming is PCH\n"); + return true; + } else { + DRM_DEBUG_KMS("Haswell detected encoder %d, assuming is CPU\n", + encoder->type); + return false; + } + } + switch (encoder->type) { case INTEL_OUTPUT_EDP: if (!intel_encoder_is_pch_edp(&encoder->base)) -- GitLab