Revert "drm/i915: try to train DP even harder"

commit 3b4f819d5eac94ba8fe5e8c061f6dabfe8d7b22c upstream.

This reverts commit 0d71068835e2610576d369d6d4cbf90e0f802a71.

Not only that the commit introduces a bogus check (voltage_tries == 5
will never meet at the inserted code path), it brings the i915 driver
into an endless dp-train loop on HP Z1 desktop machine with IVY+eDP.

At least reverting this commit recovers the framebuffer (but X is
still broken by other reasons...)

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index fb3715b4b09d26d1357fdfe16320d6680f5ee92a..2e1c10a73ecd91334c95d99dae3fa4aa8456368a 100644 (file)
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1850,7 +1850,7 @@ intel_dp_start_link_train(struct intel_dp *intel_dp)
                for (i = 0; i < intel_dp->lane_count; i++)
                        if ((intel_dp->train_set[i] & DP_TRAIN_MAX_SWING_REACHED) == 0)
                                break;
-               if (i == intel_dp->lane_count && voltage_tries == 5) {
+               if (i == intel_dp->lane_count) {
                        ++loop_tries;
                        if (loop_tries == 5) {
                                DRM_DEBUG_KMS("too many full retries, give up\n");