From 698c1aa9f83b618de79e9e5e19a58f70a4a6ae0f Mon Sep 17 00:00:00 2001
From: Lyude Paul <lyude@redhat.com>
Date: Fri, 13 Sep 2019 18:03:50 -0400
Subject: drm/nouveau/kms/nv50-: Don't create MSTMs for eDP connectors
Git-commit: 698c1aa9f83b618de79e9e5e19a58f70a4a6ae0f
Patch-mainline: v5.4-rc1
References: bsc#1152472
On the ThinkPad P71, we have one eDP connector exposed along with 5 DP
connectors, resulting in a total of 11 TMDS encoders. Since the GPU on
this system is also capable of MST, we create an additional 4 fake MST
encoders for each DP port. Unfortunately, we also do this for the eDP
port as well, resulting in:
1 eDP port: +1 TMDS encoder
+4 DPMST encoders
5 DP ports: +2 TMDS encoders
+4 DPMST encoders
*5 ports
== 35 encoders
Which breaks things, since DRM has a hard coded limit of 32 encoders.
So, fix this by not creating MSTMs for any eDP connectors. This brings
us down to 31 encoders, although we can do better.
This fixes driver probing for nouveau on the ThinkPad P71.
Signed-off-by: Lyude Paul <lyude@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
---
drivers/gpu/drm/nouveau/dispnv50/disp.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/nouveau/dispnv50/disp.c b/drivers/gpu/drm/nouveau/dispnv50/disp.c
index f1dbc7852414..064a69d161e3 100644
--- a/drivers/gpu/drm/nouveau/dispnv50/disp.c
+++ b/drivers/gpu/drm/nouveau/dispnv50/disp.c
@@ -1599,7 +1599,8 @@ nv50_sor_create(struct drm_connector *connector, struct dcb_output *dcbe)
nv_encoder->aux = aux;
}
- if ((data = nvbios_dp_table(bios, &ver, &hdr, &cnt, &len)) &&
+ if (nv_connector->type != DCB_CONNECTOR_eDP &&
+ (data = nvbios_dp_table(bios, &ver, &hdr, &cnt, &len)) &&
ver >= 0x40 && (nvbios_rd08(bios, data + 0x08) & 0x04)) {
ret = nv50_mstm_new(nv_encoder, &nv_connector->aux, 16,
nv_connector->base.base.id,
--
2.28.0