From: Rodrigo Vivi <rodrigo.vivi@intel.com>
Date: Thu, 5 Nov 2015 18:50:21 +0000 (-0800)
Subject: drm/i915: Stop tracking last calculated Sink CRC.
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=7e38eeff6da255bf0a4dfd984b40d4615456e0a4;p=linux-beck.git

drm/i915: Stop tracking last calculated Sink CRC.

It was created at 'commit aabc95dcf20 (drm/i915: Dont -ETIMEDOUT
on identical new and previous (count, crc).")' becase the counter
wasn't reliable.

Now that we properly wait for the counter to be reset we can rely
a bit more in the counter.

Also that patch stopped to return -ETIMEDOUT so the test case is
unable to skip when it is unreliable and end up in many fails
that should be skip instead.

So, with the counter more reliable we can remove
this hack that just makes things more confusing when test cases
are really expecting the same CRC and let test case skip if that's
not the case.

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index a2d26364f508..948a7b007a87 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -4011,8 +4011,6 @@ static int intel_dp_sink_crc_start(struct intel_dp *intel_dp)
 	if (!(buf & DP_TEST_CRC_SUPPORTED))
 		return -ENOTTY;
 
-	intel_dp->sink_crc.last_count = buf & DP_TEST_COUNT_MASK;
-
 	if (drm_dp_dpcd_readb(&intel_dp->aux, DP_TEST_SINK, &buf) < 0)
 		return -EIO;
 
@@ -4037,7 +4035,6 @@ int intel_dp_sink_crc(struct intel_dp *intel_dp, u8 *crc)
 	u8 buf;
 	int count, ret;
 	int attempts = 6;
-	bool old_equal_new;
 
 	ret = intel_dp_sink_crc_start(intel_dp);
 	if (ret)
@@ -4053,35 +4050,17 @@ int intel_dp_sink_crc(struct intel_dp *intel_dp, u8 *crc)
 		}
 		count = buf & DP_TEST_COUNT_MASK;
 
-		/*
-		 * Count might be reset during the loop. In this case
-		 * last known count needs to be reset as well.
-		 */
-		if (count == 0)
-			intel_dp->sink_crc.last_count = 0;
-
-		if (drm_dp_dpcd_read(&intel_dp->aux, DP_TEST_CRC_R_CR, crc, 6) < 0) {
-			ret = -EIO;
-			goto stop;
-		}
-
-		old_equal_new = (count == intel_dp->sink_crc.last_count &&
-				 !memcmp(intel_dp->sink_crc.last_crc, crc,
-					 6 * sizeof(u8)));
-
-	} while (--attempts && (count == 0 || old_equal_new));
-
-	intel_dp->sink_crc.last_count = buf & DP_TEST_COUNT_MASK;
-	memcpy(intel_dp->sink_crc.last_crc, crc, 6 * sizeof(u8));
+	} while (--attempts && count == 0);
 
 	if (attempts == 0) {
-		if (old_equal_new) {
-			DRM_DEBUG_KMS("Unreliable Sink CRC counter: Current returned CRC is identical to the previous one\n");
-		} else {
-			DRM_ERROR("Panel is unable to calculate any CRC after 6 vblanks\n");
-			ret = -ETIMEDOUT;
-			goto stop;
-		}
+		DRM_ERROR("Panel is unable to calculate any CRC after 6 vblanks\n");
+		ret = -ETIMEDOUT;
+		goto stop;
+	}
+
+	if (drm_dp_dpcd_read(&intel_dp->aux, DP_TEST_CRC_R_CR, crc, 6) < 0) {
+		ret = -EIO;
+		goto stop;
 	}
 
 stop:
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index ddc83ff443e1..0d5f7cca279e 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -740,8 +740,6 @@ enum link_m_n_set {
 
 struct sink_crc {
 	bool started;
-	u8 last_crc[6];
-	int last_count;
 };
 
 struct intel_dp {