[Intel-gfx] [PATCH 4/6] drm/i915: Cleanup if the EDP transcoder has a bobug input value

[Damien Lespiau]

In the case where the hardware has been wrongly programmed and the EDP
TRANS_DDI_FUNC_CTL register has a bogus value in its EDP Input field, we
were using the pipe variable uninitialized.

In this case, shutdown the transcoder. It will be programmed correctly
the next time we try to enabled eDP.

Signed-off-by: Damien Lespiau <damien.lespiau at intel.com>
---
 drivers/gpu/drm/i915/intel_display.c |    8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 502cb28..875baf1 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -9107,6 +9107,13 @@ void intel_modeset_setup_hw_state(struct drm_device *dev,
 			case TRANS_DDI_EDP_INPUT_C_ONOFF:
 				pipe = PIPE_C;
 				break;
+			default:
+				/* A bogus value has been programmed, disable
+				 * the transcoder */
+				WARN(1, "Bogus eDP source %08x\n", tmp);
+				intel_ddi_disable_transcoder_func(dev_priv,
+						TRANSCODER_EDP);
+				goto setup_pipes;
 			}
 
 			crtc = to_intel_crtc(dev_priv->pipe_to_crtc_mapping[pipe]);
@@ -9117,6 +9124,7 @@ void intel_modeset_setup_hw_state(struct drm_device *dev,
 		}
 	}
 
+setup_pipes:
 	for_each_pipe(pipe) {
 		crtc = to_intel_crtc(dev_priv->pipe_to_crtc_mapping[pipe]);
 
-- 
1.7.7.5