drm: fix fb-helper vs MST dangling connector ptrs (v2)

VT switch back/forth from console to xserver (for example) has potential
to go horribly wrong if a dynamic DP MST connector ends up in the saved
modeset that is restored when switching back to fbcon.

When removing a dynamic connector, don't forget to clean up the saved
state.

v1: original
v2: null out set->fb if no more connectors to avoid making i915 cranky

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1184968
Cc: stable@vger.kernel.org #v3.17+
Signed-off-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This commit is contained in:
Rob Clark 2015-01-26 10:11:08 -05:00 committed by Dave Airlie
parent 1c999c47a9
commit 2148f18fdb

View file

@ -145,6 +145,31 @@ int drm_fb_helper_add_one_connector(struct drm_fb_helper *fb_helper, struct drm_
}
EXPORT_SYMBOL(drm_fb_helper_add_one_connector);
static void remove_from_modeset(struct drm_mode_set *set,
struct drm_connector *connector)
{
int i, j;
for (i = 0; i < set->num_connectors; i++) {
if (set->connectors[i] == connector)
break;
}
if (i == set->num_connectors)
return;
for (j = i + 1; j < set->num_connectors; j++) {
set->connectors[j - 1] = set->connectors[j];
}
set->num_connectors--;
/* because i915 is pissy about this..
* TODO maybe need to makes sure we set it back to !=NULL somewhere?
*/
if (set->num_connectors == 0)
set->fb = NULL;
}
int drm_fb_helper_remove_one_connector(struct drm_fb_helper *fb_helper,
struct drm_connector *connector)
{
@ -167,6 +192,11 @@ int drm_fb_helper_remove_one_connector(struct drm_fb_helper *fb_helper,
}
fb_helper->connector_count--;
kfree(fb_helper_connector);
/* also cleanup dangling references to the connector: */
for (i = 0; i < fb_helper->crtc_count; i++)
remove_from_modeset(&fb_helper->crtc_info[i].mode_set, connector);
return 0;
}
EXPORT_SYMBOL(drm_fb_helper_remove_one_connector);