Re: [PATCH v2 05/11] iio: bmc150: refactor slope duration and threshold update

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Wed, 2015-01-28 at 11:22 +0200, Octavian Purdila wrote: 
> On Tue, Jan 6, 2015 at 8:53 PM, Srinivas Pandruvada
> <srinivas.pandruvada@xxxxxxxxxxxxxxx> wrote:
> >
> > On Sun, 2015-01-04 at 16:21 +0000, Jonathan Cameron wrote:
> > > On 21/12/14 00:42, Octavian Purdila wrote:
> > > > Move the slope duration and threshold update in separate functions
> > > > to reduce code duplicate between chip init and motion interrupt setup.
> > > >
> > > > The patch also moves the update from the motion interrupt setup
> > > > function to the write event function so that we can later refactor the
> > > > interrupt code.
> > > The side effect of this is that these will get updated at a different
> > > point in time from before.  Previously these values would only get
> > > updated when the event was enabled (or the trigger).  So to change
> > > them a disable / enable cycle was needed. Now they happen the moment
> > > they are relevant.
> > >
> > > I prefer the new option, but it is an ABI change (be it one most people
> > > won't notice!)
> > I did purposely this way.
> > IMO when user is changing critical parameters he should disable and re
> > enable to avoid undesirable side effects.
> > We have similar situation in other  thermal drivers where user can
> > change policy parameters. Initially we let them change while zone is
> > enabled (system is armed), this led to undesirable side effects due to
> > race conditions.
> >
> 
> We already have a check that prevents the change while the event is
> active. We could add a check for the data motion trigger as well, to
> avoid the above scenario.
> 
> Alternatively I can rewrite the patch to keep the current behavior and
> update the parameters when we enable the trigger.
> 
> Which one sounds better?
I prefer the second option.

Thanks,
Srinivas


--
To unsubscribe from this list: send the line "unsubscribe linux-iio" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Input]     [Linux Kernel]     [Linux SCSI]     [X.org]

  Powered by Linux