[ 36/98] Revert "drm/i915: try to train DP even harder"

Greg Kroah-Hartman
2013-03-26T22:44:04Z

From: Takashi Iwai <tiwai@suse.de>

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>

---
drivers/gpu/drm/i915/intel_dp.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- 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_d
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");