Re: [PATCH 1/3] dt/bindings: arm-pl330: add description of arm,pl330-periph-burst

[Shawn Lin]

Hi, Vinod and Lars-Peter

Ping.. Any better idea to share :)

On 2016/8/9 17:12, Shawn Lin wrote:
> Hi Lars-Peter,
>
> å 2016/8/9 16:39, Lars-Peter Clausen åé:
> > On 08/05/2016 09:25 AM, Shawn Lin wrote:
> > > Hi Vinod,
> > >
> > > å 2016/8/5 11:34, Vinod Koul åé:
> > > > On Fri, Aug 05, 2016 at 10:53:20AM +0800, Shawn Lin wrote:
> > > > > This patch adds the "arm,pl330-periph-burst" for arm-pl330 to
> > > > > support busrt mode.
> > > >
> > > > why should this be DT property. Only reason I can think of if some hw
> > > > versions support this and some won't.
> > >
> > > yes, if we want to support burst mode, both of the master(pl330) and
> > > client(several peripherals) should implement it, otherwise it will
> > > be broken when enabling.
> >
> > As you said, it is up to the consumer peripheral whether it supports
> > BURST,
> > SINGLE or both. So this is a per client property, but you specify this
> > as a
> > a global property on the producer side.
>
> Thanks for comment.
>
> yup, but what is the proper way to add it ? :)
>
>
> a) If pl330 support BURST as well as all the peripherals, we could
> enable it.
>
> b) If pl300 support BURST, but all the peripherals don't support it,
> we could not enable it.
>
> c) If pl300 support BURST, but not all the peripherals support it,
> we also could not enable it.
>
> the burst feature of peripheral IP may be vendor-specific, but the
> common driver for this peripheral are used for many many vendors which
> means we could not check all of this info. It's very likely to break
> them... I couldn't figure out how many upstreamed peripheral drivers
> who are using pl300 either.
>
> So this check should be done by all this vendors but we could make
> sure we don't break them before they check a), b), c), right?
>
>
> >


--
Best Regards
Shawn Lin