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From: Takashi Iwai <tiwai@suse.de>
To: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>,
	intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org
Subject: [PATCH] Revert "drm/i915: try to train DP even harder"
Date: Mon, 11 Mar 2013 18:40:16 +0100	[thread overview]
Message-ID: <s5h8v5tkf7j.wl%tiwai@suse.de> (raw)

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@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
 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 f61cb79..7d250aa 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1929,7 +1929,7 @@ 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");
-- 
1.8.1.4


             reply	other threads:[~2013-03-11 17:40 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-03-11 17:40 Takashi Iwai [this message]
2013-03-17 21:59 ` [PATCH] Revert "drm/i915: try to train DP even harder" Daniel Vetter
2013-03-18  9:10   ` Takashi Iwai

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