Quoting Daniel Vetter (2020-02-04 15:01:45)
We want to only take the BKL on crap drivers, but to know whether we have a crap driver we first need to look it up. Split this shuffle out from the main BKL-disabling patch, for more clarity. Historical aside: When the kernel-wide BKL was removed, it was replaced by drm_global_mutex within the scope of the drm subsystem hence why these two things are (almost) interchangeable as concepts here.
Since the minors are refcounted drm_minor_acquire is purely internal and this does not have a driver visible effect.
v2: Push the locking even further into drm_open(), suggested by Chris. This gives us more symmetry with drm_release(), and maybe a futuer avenue where we make drm_global_mutex locking (partially) opt-in like with drm_release_noglobal().
v3:
- Actually push this stuff correctly, don't unlock twice (Chris)
- Fix typo on commit message, plus explain why BKL = drm_global_mutex (Sam)
Cc: Sam Ravnborg sam@ravnborg.org Cc: Chris Wilson chris@chris-wilson.co.uk Signed-off-by: Daniel Vetter daniel.vetter@intel.com
Reviewed-by: Chris Wilson chris@chris-wilson.co.uk -Chris