drm/nouveau/dp: account for channel coding overhead in link training

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

diff --git a/drivers/gpu/drm/nouveau/nouveau_dp.c b/drivers/gpu/drm/nouveau/nouveau_dp.c
index b364465..302b2f7 100644 (file)
--- a/drivers/gpu/drm/nouveau/nouveau_dp.c
+++ b/drivers/gpu/drm/nouveau/nouveau_dp.c
@@ -422,6 +422,9 @@ nouveau_dp_link_train(struct drm_encoder *encoder, u32 datarate,
        dp.auxch = auxch->drive;
        dp.dpcd = nv_encoder->dp.dpcd;
 
+       /* adjust required bandwidth for 8B/10B coding overhead */
+       datarate = (datarate / 8) * 10;
+
        /* some sinks toggle hotplug in response to some of the actions
         * we take during link training (DP_SET_POWER is one), we need
         * to ignore them for the moment to avoid races.