There's no point in trying to clean up after driver-bugs, so just blow up. Furthermore it's an interface abuse to set no mode but have an fb and aslo to try to set an fb without enough connectors. These two spefici cases of interface abuse have been committed by the fb helper, but that's been fixed meanwhile in
commit 7e53f3a423146745a4e4bb93362d488dfad502a8 Author: Daniel Vetter daniel.vetter@ffwll.ch Date: Mon Jan 21 10:52:17 2013 +0100
drm/fb-helper: fixup set_config semantics
The i915 driver has been shipping since a while with these BUGs with no reports, so should be save.
Note that this drops an ugly case where we clear crtc->fb behind the upper levels back and so cause a refcounting mayhem, which Russell Kins spotted while trying to hunt down a drm framebuffer leak.
Reported-by: Russell King linux@arm.linux.org.uk Signed-off-by: Daniel Vetter daniel.vetter@ffwll.ch --- drivers/gpu/drm/drm_crtc_helper.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c index f554516..e57cfec 100644 --- a/drivers/gpu/drm/drm_crtc_helper.c +++ b/drivers/gpu/drm/drm_crtc_helper.c @@ -565,14 +565,13 @@ int drm_crtc_helper_set_config(struct drm_mode_set *set)
DRM_DEBUG_KMS("\n");
- if (!set) - return -EINVAL; + BUG_ON(!set); + BUG_ON(!set->crtc); + BUG_ON(!set->crtc->helper_private);
- if (!set->crtc) - return -EINVAL; - - if (!set->crtc->helper_private) - return -EINVAL; + /* Enforce sane interface api - has been abused by the fb helper. */ + BUG_ON(!set->mode && set->fb); + BUG_ON(set->fb && set->num_connectors == 0);
crtc_funcs = set->crtc->helper_private;