From 198bc7040c484d4c7be04b4eb64d5c19fbf466ce Mon Sep 17 00:00:00 2001 From: Lyude Paul Date: Fri, 13 Sep 2019 18:03:50 -0400 Subject: [PATCH] drm/nouveau/kms/nv50-: Don't create MSTMs for eDP connectors commit 698c1aa9f83b618de79e9e5e19a58f70a4a6ae0f upstream. 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 Cc: stable@vger.kernel.org Signed-off-by: Ben Skeggs Signed-off-by: Greg Kroah-Hartman --- 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 5e01bfb69d7a..10107e551fac 100644 --- a/drivers/gpu/drm/nouveau/dispnv50/disp.c +++ b/drivers/gpu/drm/nouveau/dispnv50/disp.c @@ -1517,7 +1517,8 @@ 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,