On Fri, Jan 22, 2021 at 03:06:44PM +0100, Thomas Zimmermann wrote: > Hi > > Am 22.01.21 um 14:36 schrieb Daniel Vetter: > > Requested by Thomas. I think it justifies a new level, since I tried > > to make some forward progress on this last summer, and gave up (for > > now). This is very tricky. > > Adding it to the TODO list is a first step. :) > > Acked-by: Thomas Zimmermann <tzimmermann@xxxxxxx> Applied. -Daniel > > > > > Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx> > > Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx> > > Cc: Maxime Ripard <mripard@xxxxxxxxxx> > > Cc: Thomas Zimmermann <tzimmermann@xxxxxxx> > > Cc: David Airlie <airlied@xxxxxxxx> > > Cc: Daniel Vetter <daniel@xxxxxxxx> > > Cc: Sumit Semwal <sumit.semwal@xxxxxxxxxx> > > Cc: "Christian König" <christian.koenig@xxxxxxx> > > Cc: linux-media@xxxxxxxxxxxxxxx > > Cc: linaro-mm-sig@xxxxxxxxxxxxxxxx > > --- > > Documentation/gpu/todo.rst | 19 +++++++++++++++++++ > > 1 file changed, 19 insertions(+) > > > > diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst > > index dea9082c0e5f..f872d3d33218 100644 > > --- a/Documentation/gpu/todo.rst > > +++ b/Documentation/gpu/todo.rst > > @@ -23,6 +23,9 @@ Advanced: Tricky tasks that need fairly good understanding of the DRM subsystem > > and graphics topics. Generally need the relevant hardware for development and > > testing. > > +Expert: Only attempt these if you've successfully completed some tricky > > +refactorings already and are an expert in the specific area > > + > > Subsystem-wide refactorings > > =========================== > > @@ -168,6 +171,22 @@ Contact: Daniel Vetter, respective driver maintainers > > Level: Advanced > > +Move Buffer Object Locking to dma_resv_lock() > > +--------------------------------------------- > > + > > +Many drivers have their own per-object locking scheme, usually using > > +mutex_lock(). This causes all kinds of trouble for buffer sharing, since > > +depending which driver is the exporter and importer, the locking hierarchy is > > +reversed. > > + > > +To solve this we need one standard per-object locking mechanism, which is > > +dma_resv_lock(). This lock needs to be called as the outermost lock, with all > > +other driver specific per-object locks removed. The problem is tha rolling out > > +the actual change to the locking contract is a flag day, due to struct dma_buf > > +buffer sharing. > > + > > +Level: Expert > > + > > Convert logging to drm_* functions with drm_device paramater > > ------------------------------------------------------------ > > > > -- > Thomas Zimmermann > Graphics Driver Developer > SUSE Software Solutions Germany GmbH > Maxfeldstr. 5, 90409 Nürnberg, Germany > (HRB 36809, AG Nürnberg) > Geschäftsführer: Felix Imendörffer > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch
