On Haswell, the only 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.
Signed-off-by: Eugeni Dodonov <eugeni.dodonov at intel.com>
---
drivers/gpu/drm/i915/intel_display.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index e4ebd39..b01afb0 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -3098,6 +3098,13 @@ static bool intel_crtc_driving_pch(struct drm_crtc *crtc)
if (encoder->base.crtc != crtc)
continue;
+ /* On Haswell, only DDI E can connect to PCH through FDI to drive VGA */
+ if (IS_HASWELL(dev) && (encoder->type != DRM_MODE_ENCODER_DAC)) {
+ DRM_DEBUG_KMS("Non-PCH encoder detected on Haswell. Allowed: %d, detected: %d\n",
+ DRM_MODE_ENCODER_DAC, encoder->type);
+ return false;
+ }
+
switch (encoder->type) {
case INTEL_OUTPUT_EDP:
if (!intel_encoder_is_pch_edp(&encoder->base))
--
1.7.10
