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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 <christian.koenig@amd.com>
Reviewed-by: Ken Wang <Qingqing.Wang@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
This commit is contained in:
Alex Deucher 2016-03-03 19:34:28 -05:00
parent c8213a638f
commit 02d2723475
1 changed files with 16 additions and 4 deletions
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20
drivers/gpu/drm/amd/amdgpu/atombios_dp.c
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@ -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;