[ 033/171 ] Revert "drm/i915: try to train DP even harder"

[Steven Rostedt]

3.6.11.2 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Takashi Iwai <tiwai@xxxxxxx>

[ Upstream commit 3b4f819d5eac94ba8fe5e8c061f6dabfe8d7b22c ]

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...)

Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
---
 drivers/gpu/drm/i915/intel_dp.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index ace757a..82e5e0d 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1771,7 +1771,7 @@ 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");
-- 
1.7.10.4


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