drm/i915: Avoid circular locking from intel_fbdev_fini()

lockdep spots that the fb_info->lock takes the dev->struct_mutex during
init (due to the device probing) and so we can not hold
dev->struct_mutex when unregistering the framebuffer. Simply reverse the
order of initialisation during cleanup and so do the intel_fbdev_fini()
before the intel_modeset_cleanup.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

3 files changed, 4 insertions, 7 deletions

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index df86d04f7968..726c3736082f 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -2106,6 +2106,7 @@ int i915_driver_unload(struct drm_device *dev)
         acpi_video_unregister();
 
         if (drm_core_check_feature(dev, DRIVER_MODESET)) {
+                intel_fbdev_fini(dev);
                 intel_modeset_cleanup(dev);
 
                 /*
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index f55b560c468f..69c54c5a4254 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -6130,8 +6130,6 @@ void intel_modeset_cleanup(struct drm_device *dev)
         drm_kms_helper_poll_fini(dev);
         mutex_lock(&dev->struct_mutex);
 
-        intel_fbdev_fini(dev);
-
         list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
                 /* Skip inactive CRTCs */
                 if (!crtc->fb)
diff --git a/drivers/gpu/drm/i915/intel_fb.c b/drivers/gpu/drm/i915/intel_fb.c
index 7af4accafb7f..7dc50acd65d7 100644
--- a/drivers/gpu/drm/i915/intel_fb.c
+++ b/drivers/gpu/drm/i915/intel_fb.c
@@ -206,8 +206,8 @@ static struct drm_fb_helper_funcs intel_fb_helper_funcs = {
         .fb_probe = intel_fb_find_or_create_single,
 };
 
-static int intel_fbdev_destroy(struct drm_device *dev,
-                               struct intel_fbdev *ifbdev)
+static void intel_fbdev_destroy(struct drm_device *dev,
+                                struct intel_fbdev *ifbdev)
 {
         struct fb_info *info;
         struct intel_framebuffer *ifb = &ifbdev->ifb;
@@ -225,9 +225,7 @@ static int intel_fbdev_destroy(struct drm_device *dev,
 
         drm_framebuffer_cleanup(&ifb->base);
         if (ifb->obj)
-                drm_gem_object_unreference(ifb->obj);
-
-        return 0;
+                drm_gem_object_unreference_unlocked(ifb->obj);
 }
 
 int intel_fbdev_init(struct drm_device *dev)