drm/nouveau: Fix TV-out detection on unposted cards lacking a usable DCB table.

Signed-off-by: Francisco Jerez <currojerez@riseup.net>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/drivers/gpu/drm/nouveau/nv04_display.c b/drivers/gpu/drm/nouveau/nv04_display.c
index cd70bd827614..9e28cf772e3c 100644
--- a/drivers/gpu/drm/nouveau/nv04_display.c
+++ b/drivers/gpu/drm/nouveau/nv04_display.c
@@ -78,6 +78,14 @@ nv04_display_store_initial_head_owner(struct drm_device *dev)
 int
 nv04_display_early_init(struct drm_device *dev)
 {
+        /* Make the I2C buses accessible. */
+        if (!nv_gf4_disp_arch(dev)) {
+                uint32_t pmc_enable = nv_rd32(dev, NV03_PMC_ENABLE);
+
+                if (!(pmc_enable & 1))
+                        nv_wr32(dev, NV03_PMC_ENABLE, pmc_enable | 1);
+        }
+
         /* Unlock the VGA CRTCs. */
         NVLockVgaCrtcs(dev, false);