drm/radeon/kms: handle !force case in connector detect more gracefully

When force == false, we don't do load detection in the connector
detect functions.  Unforunately, we also return the previous
connector state so we never get disconnect events for DVI-I, DVI-A,
or VGA.  Save whether we detected the monitor via load detection
previously and use that to determine whether we return the previous
state or not.

Fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=41561

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

2 files changed, 21 insertions, 3 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_connectors.c b/drivers/gpu/drm/radeon/radeon_connectors.c
index fbcf21dd2c23..9b5b3e4d2386 100644
--- a/drivers/gpu/drm/radeon/radeon_connectors.c
+++ b/drivers/gpu/drm/radeon/radeon_connectors.c
@@ -724,6 +724,7 @@ radeon_vga_detect(struct drm_connector *connector, bool force)
                 dret = radeon_ddc_probe(radeon_connector,
                                         radeon_connector->requires_extended_probe);
         if (dret) {
+                radeon_connector->detected_by_load = false;
                 if (radeon_connector->edid) {
                         kfree(radeon_connector->edid);
                         radeon_connector->edid = NULL;
@@ -750,12 +751,21 @@ radeon_vga_detect(struct drm_connector *connector, bool force)
         } else {
 
                 /* if we aren't forcing don't do destructive polling */
-                if (!force)
-                        return connector->status;
+                if (!force) {
+                        /* only return the previous status if we last
+                         * detected a monitor via load.
+                         */
+                        if (radeon_connector->detected_by_load)
+                                return connector->status;
+                        else
+                                return ret;
+                }
 
                 if (radeon_connector->dac_load_detect && encoder) {
                         encoder_funcs = encoder->helper_private;
                         ret = encoder_funcs->detect(encoder, connector);
+                        if (ret == connector_status_connected)
+                                radeon_connector->detected_by_load = true;
                 }
         }
 
@@ -897,6 +907,7 @@ radeon_dvi_detect(struct drm_connector *connector, bool force)
                 dret = radeon_ddc_probe(radeon_connector,
                                         radeon_connector->requires_extended_probe);
         if (dret) {
+                radeon_connector->detected_by_load = false;
                 if (radeon_connector->edid) {
                         kfree(radeon_connector->edid);
                         radeon_connector->edid = NULL;
@@ -964,8 +975,13 @@ radeon_dvi_detect(struct drm_connector *connector, bool force)
             (connector->connector_type == DRM_MODE_CONNECTOR_HDMIA))
                 goto out;
 
+        /* if we aren't forcing don't do destructive polling */
         if (!force) {
-                ret = connector->status;
+                /* only return the previous status if we last
+                 * detected a monitor via load.
+                 */
+                if (radeon_connector->detected_by_load)
+                        ret = connector->status;
                 goto out;
         }
 
@@ -989,6 +1005,7 @@ radeon_dvi_detect(struct drm_connector *connector, bool force)
                                         ret = encoder_funcs->detect(encoder, connector);
                                         if (ret == connector_status_connected) {
                                                 radeon_connector->use_digital = false;
+                                                radeon_connector->detected_by_load = true;
                                         }
                                 }
                                 break;
diff --git a/drivers/gpu/drm/radeon/radeon_mode.h b/drivers/gpu/drm/radeon/radeon_mode.h
index 68820f5f6303..ed0178f03235 100644
--- a/drivers/gpu/drm/radeon/radeon_mode.h
+++ b/drivers/gpu/drm/radeon/radeon_mode.h
@@ -447,6 +447,7 @@ struct radeon_connector {
         struct edid *edid;
         void *con_priv;
         bool dac_load_detect;
+        bool detected_by_load; /* if the connection status was determined by load */
         uint16_t connector_object_id;
         struct radeon_hpd hpd;
         struct radeon_router router;