[PATCH v2] drm: shmobile: Perform initialization/cleanup at probe/remove time

[Daniel Vetter]

On Tue, Dec 13, 2016 at 07:19:15PM +0200, Laurent Pinchart wrote:
> Hi Daniel,
> 
> On Tuesday 13 Dec 2016 18:11:34 Daniel Vetter wrote:
> > On Tue, Dec 13, 2016 at 02:59:48PM +0200, Laurent Pinchart wrote:
> > > From: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> > > 
> > > The drm driver .load() operation is prone to race conditions as it
> > > initializes the driver after registering the device nodes. Its usage is
> > > deprecated, inline it in the probe function and call drm_dev_alloc() and
> > > drm_dev_register() explicitly.
> > > 
> > > For consistency inline the .unload() handler in the remove function as
> > > well.
> > > 
> > > Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> > > Acked-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> > > ---
> > > Changes since v1:
> > > 
> > > - Removed manual the drm_connector_register() that caused sysfs-related
> > > 
> > >   warnings
> > 
> > Hm, what did go boom there? We should catch multiple calls to
> > drm_connector_register ...
> 
> Trying to register the connector before the DRM device is registered makes 
> sysfs unhappy due to the lack of a parent.

Autch. I think for i915 we're safe though - our trouble is that mst
hotplug starts to happen before we call drm_dev_register (but it's still
safe there already), because atm the initial topology detection works out
to be async. But we already have the drm_device at least initialized,
which I guess with DT and probe-defer isn't guaranteed.

Or does this even go boom if you just register a child before the parent?
-Daniel

> 
> > >  drivers/gpu/drm/shmobile/shmob_drm_crtc.c |   7 +-
> > >  drivers/gpu/drm/shmobile/shmob_drm_drv.c  | 206 +++++++++++-------------
> > >  2 files changed, 104 insertions(+), 109 deletions(-)
> 
> -- 
> Regards,
> 
> Laurent Pinchart
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch