On Wed, 12 Dec 2012 23:00:34 +0100 Daniel Vetter <daniel at ffwll.ch> wrote: > On Wed, Dec 12, 2012 at 12:54:47PM -0800, Jesse Barnes wrote: > > On Wed, 12 Dec 2012 14:06:44 +0100 > > Daniel Vetter <daniel.vetter at ffwll.ch> wrote: > > > > > Spinning for up to 200 us with interrupts locked out is not good. So > > > let's just spin (and even that seems to be excessive). > > > > > > And we don't call these functions from interrupt context, so this is > > > not required. Besides that doing anything in interrupt contexts which > > > might take a few hundred us is a no-go. So just convert the entire > > > thing to a mutex. Also move the mutex-grabbing out of the read/write > > > functions (add a WARN_ON(!is_locked)) instead) since all callers are > > > nicely grouped together. > > > > > > Finally the real motivation for this change: Dont grab the modeset > > > mutex in the dpio debugfs file, we don't need that consistency. And > > > correctness of the dpio interface is ensured with the dpio_lock. > > > > > > Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch> > > > > Looks fine, I guess you could convert the wait_for_atomic_us to the > > non-atomic variant now that you have a mutex. Either way: > > I like that _us purely to document the correct timeout ... Yeah we'd need a non-atomic _us variant to clean it up. No biggie. -- Jesse Barnes, Intel Open Source Technology Center
