From: Lyude Paul lyude@redhat.com
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 lyude@redhat.com Cc: stable@vger.kernel.org Signed-off-by: Ben Skeggs bskeggs@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/gpu/drm/nouveau/dispnv50/disp.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/gpu/drm/nouveau/dispnv50/disp.c +++ b/drivers/gpu/drm/nouveau/dispnv50/disp.c @@ -1603,7 +1603,8 @@ nv50_sor_create(struct drm_connector *co 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,