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Commit 169faeca authored by Daniel Vetter's avatar Daniel Vetter
Browse files

drm/fbdev-helper: Grab mode_config.mutex in drm_fb_helper_single_add_all_connectors 



This is now truly only duct-tape to keep locking checks happy since
calling this function when hpd or polling are already enabled is a
bug. The fbdev helper can't cope with hotplug changes yet at this
point, only after that.

Otoh a bit more robustness in this function can't hurt, and with this
fbdev can actually cope with hotplug changes. And it's also more
consistent with the connector hotadd/remove dp mst needs to do.
Therefore document this as new official behavior.

Reviewed-by: default avatarMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@intel.com>
parent 8c4ccc4a

drivers/gpu/drm/drm_fb_helper.c

+7 −2
Original line number Diff line number Diff line
@@ -89,8 +89,9 @@ static LIST_HEAD(kernel_fb_helper_list); 
 * connectors to the fbdev, e.g. if some are reserved for special purposes or

 * not adequate to be used for the fbcon.

 *

 * Since this is part of the initial setup before the fbdev is published, no

 * locking is required.

 * This function is protected against concurrent connector hotadds/removals

 * using drm_fb_helper_add_one_connector() and

 * drm_fb_helper_remove_one_connector().

 */

int drm_fb_helper_single_add_all_connectors(struct drm_fb_helper *fb_helper)

{
@@ -98,6 +99,7 @@ int drm_fb_helper_single_add_all_connectors(struct drm_fb_helper *fb_helper) 
	struct drm_connector *connector;

	int i;



	mutex_lock(&dev->mode_config.mutex);

	drm_for_each_connector(connector, dev) {

		struct drm_fb_helper_connector *fb_helper_connector;
@@ -108,6 +110,7 @@ int drm_fb_helper_single_add_all_connectors(struct drm_fb_helper *fb_helper) 
		fb_helper_connector->connector = connector;

		fb_helper->connector_info[fb_helper->connector_count++] = fb_helper_connector;

	}

	mutex_unlock(&dev->mode_config.mutex);

	return 0;

fail:

	for (i = 0; i < fb_helper->connector_count; i++) {
@@ -115,6 +118,8 @@ int drm_fb_helper_single_add_all_connectors(struct drm_fb_helper *fb_helper) 
		fb_helper->connector_info[i] = NULL;

	}

	fb_helper->connector_count = 0;

	mutex_unlock(&dev->mode_config.mutex);



	return -ENOMEM;

}

EXPORT_SYMBOL(drm_fb_helper_single_add_all_connectors);