[PATCH] drm: Add a debug message when getting a prop is missing

From: Mark Yacoub
Date: Tue May 10 2022 - 14:28:33 EST


[Why]
If a connector property is attached but
drm_atomic_connector_get_property doesn't handle a case for it,
modeteset will crash with a segfault without.

[How]
Add a debug message indicating that a connector property is not handled
when user space is trying to read it.

TEST=modetest

Signed-off-by: Mark Yacoub <markyacoub@xxxxxxxxxxxx>
---
drivers/gpu/drm/drm_atomic_uapi.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c
index acb1ee93d206..36b0f664dd80 100644
--- a/drivers/gpu/drm/drm_atomic_uapi.c
+++ b/drivers/gpu/drm/drm_atomic_uapi.c
@@ -884,6 +884,12 @@ drm_atomic_connector_get_property(struct drm_connector *connector,
return connector->funcs->atomic_get_property(connector,
state, property, val);
} else {
+ // LOG that the kernel is missing handling this property as a case here.
+ drm_dbg_atomic(
+ dev,
+ "[CONNECTOR:%d:%s] Get Property [PROP:%d:%s] is not handled\n",
+ connector->base.id, connector->name, property->base.id,
+ property->name);
return -EINVAL;
}

--
2.36.0.512.ge40c2bad7a-goog