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 <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 02d27234759dc4fe14a880ec1e1dee108cb0b503 Mon Sep 17 00:00:00 2001
From: Alex Deucher <alexander.deucher@xxxxxxx>
Date: Thu, 3 Mar 2016 19:34:28 -0500
Subject: [PATCH] drm/amdgpu/dp: add back special handling for NUTMEG
MIME-Version: 1.0
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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 <christian.koenig@xxxxxxx>
Reviewed-by: Ken Wang <Qingqing.Wang@xxxxxxx>
Reviewed-by: Harry Wentland <harry.wentland@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
diff --git a/drivers/gpu/drm/amd/amdgpu/atombios_dp.c b/drivers/gpu/drm/amd/amdgpu/atombios_dp.c
index 21aacc1f45c1..bf731e9f643e 100644
--- a/drivers/gpu/drm/amd/amdgpu/atombios_dp.c
+++ b/drivers/gpu/drm/amd/amdgpu/atombios_dp.c
@@ -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;
--
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