For largely legacy reasons, a global mutex (drm_global_mutex) is taken around open/close of the drm_device, including serialising the filp release. For drivers with their own fine grained locking, such global coordination is a hindrance, albeit off the common hot paths.
References: 7a2c65dd32b1 ("drm: Release filp before global lock") Signed-off-by: Chris Wilson chris@chris-wilson.co.uk Cc: Ben Skeggs bskeggs@redhat.com --- drivers/gpu/drm/nouveau/nouveau_drm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/nouveau/nouveau_drm.c b/drivers/gpu/drm/nouveau/nouveau_drm.c index b65ae817eabf..2d65a6c27456 100644 --- a/drivers/gpu/drm/nouveau/nouveau_drm.c +++ b/drivers/gpu/drm/nouveau/nouveau_drm.c @@ -1092,7 +1092,7 @@ static const struct file_operations nouveau_driver_fops = { .owner = THIS_MODULE, .open = drm_open, - .release = drm_release, + .release = drm_release_noglobal, .unlocked_ioctl = nouveau_drm_ioctl, .mmap = nouveau_ttm_mmap, .poll = drm_poll,