drm/nv50-/kms: pass a non-zero value for head to sor dpms methods

There's Apple machines out there which (probably completely arbitrarily)
restrict each output path to a particular head.  This causes us to not
be able to locate the output data needed to power on/off the DP output
correctly.

We fix this by passing in a head index we know is valid (as opposed to
"head 0").

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

diff --git a/drivers/gpu/drm/nouveau/nv50_display.c b/drivers/gpu/drm/nouveau/nv50_display.c
index afdf607df3e6e432d122845abed5502c4a3938d5..4c534b7b04daf032d29efdfc6365011eba2a74cf 100644 (file)
--- a/drivers/gpu/drm/nouveau/nv50_display.c
+++ b/drivers/gpu/drm/nouveau/nv50_display.c
@@ -1741,7 +1741,8 @@ nv50_sor_dpms(struct drm_encoder *encoder, int mode)
                }
        }
 
-       mthd  = (ffs(nv_encoder->dcb->sorconf.link) - 1) << 2;
+       mthd  = (ffs(nv_encoder->dcb->heads) - 1) << 3;
+       mthd |= (ffs(nv_encoder->dcb->sorconf.link) - 1) << 2;
        mthd |= nv_encoder->or;
 
        if (nv_encoder->dcb->type == DCB_OUTPUT_DP) {