drm/nv50: fix duallink_possible calculation for DCB 4.0 cards

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

diff --git a/drivers/gpu/drm/nouveau/nouveau_bios.c b/drivers/gpu/drm/nouveau/nouveau_bios.c
index b3c7a87..9f30fb8 100644 (file)
--- a/drivers/gpu/drm/nouveau/nouveau_bios.c
+++ b/drivers/gpu/drm/nouveau/nouveau_bios.c
@@ -5536,12 +5536,6 @@ parse_dcb20_entry(struct drm_device *dev, struct dcb_table *dcb,
        entry->bus = (conn >> 16) & 0xf;
        entry->location = (conn >> 20) & 0x3;
        entry->or = (conn >> 24) & 0xf;
-       /*
-        * Normal entries consist of a single bit, but dual link has the
-        * next most significant bit set too
-        */
-       entry->duallink_possible =
-                       ((1 << (ffs(entry->or) - 1)) * 3 == entry->or);
 
        switch (entry->type) {
        case OUTPUT_ANALOG:
@@ -5625,6 +5619,16 @@ parse_dcb20_entry(struct drm_device *dev, struct dcb_table *dcb,
                break;
        }
 
+       if (dcb->version < 0x40) {
+               /* Normal entries consist of a single bit, but dual link has
+                * the next most significant bit set too
+                */
+               entry->duallink_possible =
+                       ((1 << (ffs(entry->or) - 1)) * 3 == entry->or);
+       } else {
+               entry->duallink_possible = (entry->sorconf.link == 3);
+       }
+
        /* unsure what DCB version introduces this, 3.0? */
        if (conf & 0x100000)
                entry->i2c_upper_default = true;