From fafa8b5c9f7426cef6b9b52b8582a867edbc7a06 Mon Sep 17 00:00:00 2001 From: Ben Skeggs Date: Fri, 19 May 2017 23:59:35 +1000 Subject: [PATCH] drm/nouveau/disp/dp: use cached link configuration when checking link status Saves some trips across the aux channel. Signed-off-by: Ben Skeggs --- drivers/gpu/drm/nouveau/nvkm/engine/disp/dp.c | 39 ++++++++++++--------------- 1 file changed, 17 insertions(+), 22 deletions(-) diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/dp.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/dp.c index 2b3aca0..4941643 100644 --- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/dp.c +++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/dp.c @@ -326,7 +326,7 @@ static const struct dp_rates { {} }; -static void +static int nvkm_dp_train(struct nvkm_dp *dp) { struct nv50_disp *disp = nv50_disp(dp->outp.disp); @@ -370,39 +370,34 @@ nvkm_dp_train(struct nvkm_dp *dp) nvkm_dp_train_fini(dp); if (ret < 0) OUTP_ERR(&dp->outp, "training failed"); - - OUTP_DBG(&dp->outp, "training done"); + else + OUTP_DBG(&dp->outp, "training done"); atomic_set(&dp->lt.done, 1); + return ret; } int -nvkm_output_dp_train(struct nvkm_outp *outp, u32 datarate) +nvkm_output_dp_train(struct nvkm_outp *outp, u32 datakbps) { struct nvkm_dp *dp = nvkm_dp(outp); + struct nvkm_ior *ior = dp->outp.ior; bool retrain = true; - u8 link[2], stat[3]; - u32 linkrate; + u32 linkKBps; + u32 dataKBps; + u8 stat[3]; int ret, i; mutex_lock(&dp->mutex); - /* check that the link is trained at a high enough rate */ - ret = nvkm_rdaux(dp->aux, DPCD_LC00_LINK_BW_SET, link, 2); - if (ret) { - OUTP_DBG(&dp->outp, - "failed to read link config, assuming no sink"); - goto done; - } - - linkrate = link[0] * 27000 * (link[1] & DPCD_LC01_LANE_COUNT_SET); - linkrate = (linkrate * 8) / 10; /* 8B/10B coding overhead */ - datarate = (datarate + 9) / 10; /* -> decakilobits */ - if (linkrate < datarate) { - OUTP_DBG(&dp->outp, "link not trained at sufficient rate"); + /* Check that link configuration meets current requirements. */ + linkKBps = ior->dp.bw * 27000 * ior->dp.nr; + dataKBps = DIV_ROUND_UP(datakbps, 8); + if (linkKBps < dataKBps) { + OUTP_DBG(&dp->outp, "link requirements changed"); goto done; } - /* check that link is still trained */ + /* Check that link is still trained. */ ret = nvkm_rdaux(dp->aux, DPCD_LS02, stat, 3); if (ret) { OUTP_DBG(&dp->outp, @@ -411,7 +406,7 @@ nvkm_output_dp_train(struct nvkm_outp *outp, u32 datarate) } if (stat[2] & DPCD_LS04_INTERLANE_ALIGN_DONE) { - for (i = 0; i < (link[1] & DPCD_LC01_LANE_COUNT_SET); i++) { + for (i = 0; i < ior->dp.nr; i++) { u8 lane = (stat[i >> 1] >> ((i & 1) * 4)) & 0x0f; if (!(lane & DPCD_LS02_LANE0_CR_DONE) || !(lane & DPCD_LS02_LANE0_CHANNEL_EQ_DONE) || @@ -435,7 +430,7 @@ done: dp->dpcd[DPCD_RC02] = dp->outp.info.dpconf.link_nr; } - nvkm_dp_train(dp); + ret = nvkm_dp_train(dp); } mutex_unlock(&dp->mutex); -- 2.7.4