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[1/4] drm/nouveau: dispnv50: Don't create MSTMs for eDP connectors

Message ID 20190913220355.6883-1-lyude@redhat.com (mailing list archive)
State New, archived
Headers show
Series [1/4] drm/nouveau: dispnv50: Don't create MSTMs for eDP connectors | expand

Commit Message

Lyude Paul Sept. 13, 2019, 10:03 p.m. UTC
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
---
 drivers/gpu/drm/nouveau/dispnv50/disp.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/gpu/drm/nouveau/dispnv50/disp.c b/drivers/gpu/drm/nouveau/dispnv50/disp.c
index 307584107d77..b46be8a091e9 100644
--- 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 *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,