From 2148f18fdb45f31ca269a7787fbc24053cd42e70 Mon Sep 17 00:00:00 2001 From: Rob Clark Date: Mon, 26 Jan 2015 10:11:08 -0500 Subject: [PATCH] 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 Signed-off-by: Dave Airlie --- drivers/gpu/drm/drm_fb_helper.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index cf775a4..dc386eb 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -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); -- 2.7.4