[PATCH 28/50] drm: Remove DRM_WAIT_ON from all drivers

[Daniel Vetter]

On Wed, Dec 18, 2013 at 11:39:27AM +1000, Dave Airlie wrote:
> On Wed, Dec 11, 2013 at 8:34 PM, Daniel Vetter <daniel.vetter at ffwll.ch> wrote:
> > Since this is all old ums stuff (including the one in the radeon
> > driver) I've just tried to perfectly replicate the existing semantics.
> >
> > Reinventing wait queue code with semantics that differ from all the
> > standard linux wait functions is just hairy, so now we can get rid of
> > this and so make sure it'll never again be used.
> >
> > Oh and: via futexes ... *shudder*
> 
> This one worries me, I've had numerous attempts to rip this out in the
> past and they always changed semantics on some devices and broke
> stuff.
> 
> The sneaky timeout is essential for a lot of the hardware
> 
> http://marc.info/?l=dri-devel&m=111383274225047&w=1
> 
> So I think I'd like a few more people to review this one before I go
> near it again :-)

Oh, and I've thought the only tricky stuff is mapping the errno's
correctly. I think if we have such cases of racy drivers then the right
thing to do is to shovel this macro into drivers and slap a big comment
about signalling races on top of that code.

Thomas report doesn't say so, but I guess it's for via. Thomas, do you
still have a vague recollection of what this has been about?

Dave, do you want me to just respin this one with via left as-is (and the
macro pushed into the via driver)?

Thanks, Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch