Driver's and ->fill_modes functions are allowed to grab crtc mutexes (for e.g. load detect). Hence we need to first only grab the general kms mutex, and only in a second step grab all locks to do the modesets.
This prevents a deadlock on my gm45 in the tv load detect code called by drm_helper_probe_single_connector_modes.
Cc: Dave Airlie airlied@gmail.com Signed-off-by: Daniel Vetter daniel.vetter@ffwll.ch --- drivers/gpu/drm/drm_fb_helper.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index 6764dce..b78cbe7 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -1551,10 +1551,10 @@ int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper) if (!fb_helper->fb) return 0;
- drm_modeset_lock_all(dev); + mutex_lock(&fb_helper->dev->mode_config.mutex); if (!drm_fb_helper_is_bound(fb_helper)) { fb_helper->delayed_hotplug = true; - drm_modeset_unlock_all(dev); + mutex_unlock(&fb_helper->dev->mode_config.mutex); return 0; } DRM_DEBUG_KMS("\n"); @@ -1565,9 +1565,11 @@ int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
count = drm_fb_helper_probe_connector_modes(fb_helper, max_width, max_height); + mutex_unlock(&fb_helper->dev->mode_config.mutex); + + drm_modeset_lock_all(dev); drm_setup_crtcs(fb_helper); drm_modeset_unlock_all(dev); - drm_fb_helper_set_par(fb_helper->fbdev);
return 0;