[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Message-ID: <1361460443.648613272@f272.mail.ru>
Date: Thu, 21 Feb 2013 19:27:23 +0400
From: Alexander Shiyan <shc_work@...l.ru>
To: Arnd Bergmann <arnd@...db.de>
Cc: Dong Aisheng <dong.aisheng@...aro.org>,
linux-kernel@...r.kernel.org,
Samuel Ortiz <sameo@...ux.intel.com>,
Mark Brown <broonie@...nsource.wolfsonmicro.com>
Subject: Re[16]: [PATCH v3] mfd: syscon: Add non-DT support
...
> > > > > treat the absence of DT information as an error, and a call to
> > > > > syscon_regmap_lookup_by_compatible or syscon_regmap_lookup_by_phandle
> > > > > will always return the syscon device that was registered first, or
> > > > > -EPROBE_DEFER for any error.
> > > >
> > > > The initial idea is search desired syscon device from drivers only by one function
> > > > (i.e. search syscon device by compatible string or by specific alias) and no depend
> > > > on DT or non-DT. I.e. define syscon device always at machine start (even if we run
> > > > machine from DTS), because device should be always present in system.
> > >
> > > I don't understand yet what the advantage for clps711x is over just a single
> > > register area that would get registered at boot time and replace all the
> > > clps_readl/clps_writel calls.
> >
> > This cause a serious perfomance impact. Only SYSCON and SYSFLG is used
> > in several places and should be protected by spinlocks. Other registers
> > can be used without locks. And, as say before, clps_read/write will be replaced with
> > read/write when registers will passed as resource. First example of this change I
> > sent to you before (patchset for serial driver).
>
> Yes, that makes sense. I have no fundamental objections then. I'll wait
> for the next version of your patch and then comment on any details I still
> find sticking out.
OK. Next version will be sent in few minutes.
I am leave search by id_entry and extend it with variant from first patch version.
This will allow to search syscon device with id_entry record in the driver, and
without last one by specifying generic name with id (for example "syscon.0").
Thanks.
---
Powered by blists - more mailing lists