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FAILED: patch "[PATCH] drm/amdgpu/dp: add back special handling for NUTMEG" failed to apply to 4.4-stable tree

PATCH [email protected] 1 participant 1 message Mar 12, 2016

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Stable branch DRM drivers Radeon and amdgpu DRM drivers
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The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

Quoted 1 line

From 02d27234759dc4fe14a880ec1e1dee108cb0b503 Mon Sep 17 00:00:00 2001

From: Alex Deucher <[email protected]>
Date: Thu, 3 Mar 2016 19:34:28 -0500
Subject: [PATCH] drm/amdgpu/dp: add back special handling for NUTMEG
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When I fixed the dp rate selection in:
3b73b168cffd9c392584d3f665021fa2190f8612 drm/amdgpu: fix dp link rate selection (v2) I accidently dropped the special handling for NUTMEG DP bridge chips. They require a fixed link rate.

Reviewed-by Christian König <[email protected]>
Reviewed-by Ken Wang <[email protected]>
Reviewed-by Harry Wentland <[email protected]>
Signed-off-by Alex Deucher <[email protected]>
Cc [email protected]
drivers/gpu/drm/amd/amdgpu/atombios_dp.c +16 -4
index 21aacc1f45c1..bf731e9f643e 100644
@@ -265,15 +265,27 @@ static int amdgpu_atombios_dp_get_dp_link_config(struct drm_connector *connector
 	unsigned max_lane_num = drm_dp_max_lane_count(dpcd);
 	unsigned lane_num, i, max_pix_clock;
 
-	for (lane_num = 1; lane_num <= max_lane_num; lane_num <<= 1) {
-		for (i = 0; i < ARRAY_SIZE(link_rates) && link_rates[i] <= max_link_rate; i++) {
-			max_pix_clock = (lane_num * link_rates[i] * 8) / bpp;
+	if (amdgpu_connector_encoder_get_dp_bridge_encoder_id(connector) ==
+	    ENCODER_OBJECT_ID_NUTMEG) {
+		for (lane_num = 1; lane_num <= max_lane_num; lane_num <<= 1) {
+			max_pix_clock = (lane_num * 270000 * 8) / bpp;
 			if (max_pix_clock >= pix_clock) {
 				*dp_lanes = lane_num;
-				*dp_rate = link_rates[i];
+				*dp_rate = 270000;
 				return 0;
 			}
 		}
+	} else {
+		for (lane_num = 1; lane_num <= max_lane_num; lane_num <<= 1) {
+			for (i = 0; i < ARRAY_SIZE(link_rates) && link_rates[i] <= max_link_rate; i++) {
+				max_pix_clock = (lane_num * link_rates[i] * 8) / bpp;
+				if (max_pix_clock >= pix_clock) {
+					*dp_lanes = lane_num;
+					*dp_rate = link_rates[i];
+					return 0;
+				}
+			}
+		}
 	}
 
 	return -EINVAL;