drm/radeon/kms: enable hpd support

This enabled interrupt driven hpd support for all
radeon chips.  Assuming the hpd pin is wired up
correctly, the driver will generate uevents on
digital monitor connect and disconnect and retrain
DP monitors automatically.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/drivers/gpu/drm/radeon/atombios_dp.c b/drivers/gpu/drm/radeon/atombios_dp.c
index 784ba80afcb6..0d63c4436e7c 100644
--- a/drivers/gpu/drm/radeon/atombios_dp.c
+++ b/drivers/gpu/drm/radeon/atombios_dp.c
@@ -507,6 +507,18 @@ static bool atom_dp_get_link_status(struct radeon_connector *radeon_connector,
         return true;
 }
 
+bool radeon_dp_needs_link_train(struct radeon_connector *radeon_connector)
+{
+        struct radeon_connector_atom_dig *dig_connector = radeon_connector->con_priv;
+        u8 link_status[DP_LINK_STATUS_SIZE];
+
+        if (!atom_dp_get_link_status(radeon_connector, link_status))
+                return false;
+        if (dp_channel_eq_ok(link_status, dig_connector->dp_lane_count))
+                return false;
+        return true;
+}
+
 static void dp_set_power(struct radeon_connector *radeon_connector, u8 power_state)
 {
         struct radeon_connector_atom_dig *dig_connector = radeon_connector->con_priv;