From: Dave Airlie <airl...@redhat.com>
As suggested by Daniel, if we are actively using the connector in a modeset
we don't want it to disappear from underneath us. This takes a reference
to the connector in the atomic paths when we are setting the state up,
and in the non-atomic paths when binding the encoder.
Signed-off-by: Dave Airlie <airlied at redhat.com>
---
drivers/gpu/drm/drm_atomic.c | 11 ++++++++++-
drivers/gpu/drm/drm_crtc_helper.c | 6 ++++++
2 files changed, 16 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 9d5e3c8..d899dac 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -1159,7 +1159,7 @@ drm_atomic_set_crtc_for_connector(struct
drm_connector_state *conn_state,
struct drm_crtc *crtc)
{
struct drm_crtc_state *crtc_state;
-
+ bool had_crtc = conn_state->crtc ? true : false;
if (conn_state->crtc && conn_state->crtc != crtc) {
crtc_state =
drm_atomic_get_existing_crtc_state(conn_state->state,
conn_state->crtc);
@@ -1179,6 +1179,15 @@ drm_atomic_set_crtc_for_connector(struct
drm_connector_state *conn_state,
conn_state->crtc = crtc;
+ /* If we had no crtc then got one, add a reference,
+ * if we had a crtc and are going to none, drop a reference,
+ * otherwise just keep the reference we have.
+ */
+ if (!had_crtc && crtc)
+ drm_connector_reference(conn_state->connector);
+ else if (!crtc && had_crtc)
+ drm_connector_unreference(conn_state->connector);
+
if (crtc)
DRM_DEBUG_ATOMIC("Link connector state %p to [CRTC:%d:%s]\n",
conn_state, crtc->base.id, crtc->name);
diff --git a/drivers/gpu/drm/drm_crtc_helper.c
b/drivers/gpu/drm/drm_crtc_helper.c
index 79555d2..71b6c72 100644
--- a/drivers/gpu/drm/drm_crtc_helper.c
+++ b/drivers/gpu/drm/drm_crtc_helper.c
@@ -456,6 +456,9 @@ drm_crtc_helper_disable(struct drm_crtc *crtc)
* between them is henceforth no longer available.
*/
connector->dpms = DRM_MODE_DPMS_OFF;
+
+ /* we keep a reference while the encoder is bound */
+ drm_connector_unreference(connector);
}
}
@@ -635,9 +638,12 @@ int drm_crtc_helper_set_config(struct drm_mode_set *set)
mode_changed = true;
/* If the encoder is reused for another connector, then
* the appropriate crtc will be set later.
+ * take a reference only if we haven't had an encoder
before.
*/
if (connector->encoder)
connector->encoder->crtc = NULL;
+ else
+ drm_connector_reference(connector);
connector->encoder = new_encoder;
}
}
--
2.5.5
