From 0713b4510e62411071b748d786043cdaada56ce5 Mon Sep 17 00:00:00 2001
From: Ben Skeggs <bskeggs@redhat.com>
Date: Tue, 1 Jul 2014 10:54:52 +1000
Subject: [PATCH] drm/nouveau/dp: fix required link bandwidth calculations
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
---
drivers/gpu/drm/nouveau/core/engine/disp/nv50.c | 6 +++---
drivers/gpu/drm/nouveau/core/engine/disp/nvd0.c | 6 +++---
drivers/gpu/drm/nouveau/core/engine/disp/outpdp.c | 8 +++++---
3 files changed, 11 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/nouveau/core/engine/disp/nv50.c b/drivers/gpu/drm/nouveau/core/engine/disp/nv50.c
index 26e962b7e702a0..2283c442a10d48 100644
--- a/drivers/gpu/drm/nouveau/core/engine/disp/nv50.c
+++ b/drivers/gpu/drm/nouveau/core/engine/disp/nv50.c
@@ -1516,11 +1516,11 @@ nv50_disp_intr_unk20_2(struct nv50_disp_priv *priv, int head)
}
switch ((ctrl & 0x000f0000) >> 16) {
- case 6: datarate = pclk * 30 / 8; break;
- case 5: datarate = pclk * 24 / 8; break;
+ case 6: datarate = pclk * 30; break;
+ case 5: datarate = pclk * 24; break;
case 2:
default:
- datarate = pclk * 18 / 8;
+ datarate = pclk * 18;
break;
}
diff --git a/drivers/gpu/drm/nouveau/core/engine/disp/nvd0.c b/drivers/gpu/drm/nouveau/core/engine/disp/nvd0.c
index 48aa38a87e3fdb..fa30d8196f3592 100644
--- a/drivers/gpu/drm/nouveau/core/engine/disp/nvd0.c
+++ b/drivers/gpu/drm/nouveau/core/engine/disp/nvd0.c
@@ -1159,11 +1159,11 @@ nvd0_disp_intr_unk2_2(struct nv50_disp_priv *priv, int head)
if (outp->info.type == DCB_OUTPUT_DP) {
u32 sync = nv_rd32(priv, 0x660404 + (head * 0x300));
switch ((sync & 0x000003c0) >> 6) {
- case 6: pclk = pclk * 30 / 8; break;
- case 5: pclk = pclk * 24 / 8; break;
+ case 6: pclk = pclk * 30; break;
+ case 5: pclk = pclk * 24; break;
case 2:
default:
- pclk = pclk * 18 / 8;
+ pclk = pclk * 18;
break;
}
diff --git a/drivers/gpu/drm/nouveau/core/engine/disp/outpdp.c b/drivers/gpu/drm/nouveau/core/engine/disp/outpdp.c
index 52c299c3d3008e..eb2d7789555d42 100644
--- a/drivers/gpu/drm/nouveau/core/engine/disp/outpdp.c
+++ b/drivers/gpu/drm/nouveau/core/engine/disp/outpdp.c
@@ -34,7 +34,7 @@ nvkm_output_dp_train(struct nvkm_output *base, u32 datarate, bool wait)
struct nvkm_output_dp *outp = (void *)base;
bool retrain = true;
u8 link[2], stat[3];
- u32 rate;
+ u32 linkrate;
int ret, i;
/* check that the link is trained at a high enough rate */
@@ -44,8 +44,10 @@ nvkm_output_dp_train(struct nvkm_output *base, u32 datarate, bool wait)
goto done;
}
- rate = link[0] * 27000 * (link[1] & DPCD_LC01_LANE_COUNT_SET);
- if (rate < ((datarate / 8) * 10)) {
+ 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) {
DBG("link not trained at sufficient rate\n");
goto done;
}
--
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