[PATCH] drm: WARN() when drm_connector_attach_property fails

[Paulo Zanoni <przanoni@gmail.com>]

From: Paulo Zanoni <paulo.r.zanoni@intel.com>

Also return void instead of int. We have more than 100 callers and
no one checks for the return value.

If this function fails the property won't be exposed by the get/set
ioctls, but we should probably survive. If this starts happening,
the solution will be to increase DRM_CONNECTOR_MAX_PROPERTY and
recompile the Kernel.

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
---
 drivers/gpu/drm/drm_crtc.c |   10 +++++-----
 include/drm/drm_crtc.h     |    4 ++--
 2 files changed, 7 insertions(+), 7 deletions(-)

>From the previous patch series sent, the only comment this patch had was this,
from Chris:

> Please add that to the error message and use printk_once() since we only
> really want to annoy the user the first time.

For each time we see the message, we need to increase the value by 1, so instead
of using printk_once, I just added this information to the message. Anyway, we
shouldn't be seeing this message too many times, since we don't add new
properties that often.

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 0a22ef8..37bb7ab 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -2819,7 +2819,7 @@ void drm_property_destroy(struct drm_device *dev, struct drm_property *property)
 }
 EXPORT_SYMBOL(drm_property_destroy);
 
-int drm_connector_attach_property(struct drm_connector *connector,
+void drm_connector_attach_property(struct drm_connector *connector,
 			       struct drm_property *property, uint64_t init_val)
 {
 	int i;
@@ -2828,13 +2828,13 @@ int drm_connector_attach_property(struct drm_connector *connector,
 		if (connector->property_ids[i] == 0) {
 			connector->property_ids[i] = property->base.id;
 			connector->property_values[i] = init_val;
-			break;
+			return;
 		}
 	}
 
-	if (i == DRM_CONNECTOR_MAX_PROPERTY)
-		return -EINVAL;
-	return 0;
+	WARN(1, "Failed to attach connector property. Please increase "
+		"DRM_CONNECTOR_MAX_PROPERTY by 1 for each time you see this "
+		"message\n");
 }
 EXPORT_SYMBOL(drm_connector_attach_property);
 
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index f35e7ed..036faec 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -910,8 +910,8 @@ extern int drmfb_remove(struct drm_device *dev, struct drm_framebuffer *fb);
 extern void drm_crtc_probe_connector_modes(struct drm_device *dev, int maxX, int maxY);
 extern bool drm_crtc_in_use(struct drm_crtc *crtc);
 
-extern int drm_connector_attach_property(struct drm_connector *connector,
-				      struct drm_property *property, uint64_t init_val);
+extern void drm_connector_attach_property(struct drm_connector *connector,
+					  struct drm_property *property, uint64_t init_val);
 extern struct drm_property *drm_property_create(struct drm_device *dev, int flags,
 						const char *name, int num_values);
 extern struct drm_property *drm_property_create_enum(struct drm_device *dev, int flags,
-- 
1.7.10