Without this when a MST connector is removed drm_atomic_helper_set_config can complain about set->mode && !set->num_connectors.
------------[ cut here ]------------ WARNING: CPU: 2 PID: 2403 at drivers/gpu/drm/drm_atomic_helper.c:1673 drm_atomic_helper_set_config+0x22e/0x420() CPU: 2 PID: 2403 Comm: kms_flip Not tainted 4.2.0-rc5 #4233 Hardware name: NUC5i7RYB, BIOS RYBDWi35.86A.0246.2015.0309.1355 03/09/2015 ffffffff81ac75e8 ffff88004e4ffbf8 ffffffff81714c34 0000000080000000 0000000000000000 ffff88004e4ffc38 ffffffff8107bf81 ffff88004e4ffc48 ffff8800d8ca0690 ffff8800d8d7a080 ffff8800d8cc2290 ffff8800d07bc9f0 Call Trace: [<ffffffff81714c34>] dump_stack+0x4f/0x7b [<ffffffff8107bf81>] warn_slowpath_common+0x81/0xc0 [<ffffffff8107c065>] warn_slowpath_null+0x15/0x20 [<ffffffff813d9e3e>] drm_atomic_helper_set_config+0x22e/0x420 [<ffffffff813da174>] ? drm_atomic_helper_plane_set_property+0x84/0xc0 [<ffffffff813ee101>] drm_mode_set_config_internal+0x61/0x100 [<ffffffff813dc4ed>] restore_fbdev_mode+0xbd/0xe0 [<ffffffff813de1e4>] drm_fb_helper_restore_fbdev_mode_unlocked+0x24/0x70 [<ffffffffc0123d11>] intel_fbdev_restore_mode+0x21/0x80 [i915] [<ffffffffc014bf69>] i915_driver_lastclose+0x9/0x10 [i915] [<ffffffff813e2429>] drm_lastclose+0x29/0x130 [<ffffffff813e2844>] drm_release+0x314/0x500 [<ffffffff81194795>] __fput+0xe5/0x1f0 [<ffffffff811948d9>] ____fput+0x9/0x10 [<ffffffff810968d8>] task_work_run+0x88/0xb0 [<ffffffff8107d53f>] do_exit+0x37f/0xa90 [<ffffffff8127e258>] ? selinux_file_ioctl+0x48/0xc0 [<ffffffff81277dfe>] ? security_file_ioctl+0x3e/0x60 [<ffffffff8107ec80>] do_group_exit+0x40/0xa0 [<ffffffff8107ecef>] SyS_exit_group+0xf/0x10 [<ffffffff8171bdd7>] entry_SYSCALL_64_fastpath+0x12/0x6a ---[ end trace 0daf358c49351567 ]--- Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com> --- drivers/gpu/drm/drm_fb_helper.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index 5875059a7625..418d299f3b12 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -168,11 +168,14 @@ static void remove_from_modeset(struct drm_mode_set *set, } 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) + if (set->num_connectors == 0) { set->fb = NULL; + drm_mode_destroy(connector->dev, set->mode); + set->mode = NULL; + } } int drm_fb_helper_remove_one_connector(struct drm_fb_helper *fb_helper, -- 2.1.0