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Date:   Tue, 16 Jun 2020 23:13:43 +0300
From:   Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To:     Maxim Uvarov <maxim.uvarov@linaro.org>
Cc:     Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        "tee-dev @ lists . linaro . org" <tee-dev@lists.linaro.org>,
        peterhuewe@gmx.de, Jason Gunthorpe <jgg@ziepe.ca>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jens Wiklander <jens.wiklander@linaro.org>,
        linux-integrity@vger.kernel.org, Arnd Bergmann <arnd@linaro.org>,
        Sumit Garg <sumit.garg@linaro.org>
Subject: Re: [PATCHv6 1/3] optee: use uuid for sysfs driver entry
Message-ID: <20200616201343.GE10412@linux.intel.com>
References: <20200601150645.13412-1-maxim.uvarov@linaro.org>
 <20200601150645.13412-2-maxim.uvarov@linaro.org>
 <20200604083655.GA4026@linux.intel.com>
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On Thu, Jun 04, 2020 at 12:16:21PM +0300, Maxim Uvarov wrote:
> On Thu, 4 Jun 2020 at 11:37, Jarkko Sakkinen
> <jarkko.sakkinen@linux.intel.com> wrote:
> >
> > On Mon, Jun 01, 2020 at 06:06:43PM +0300, Maxim Uvarov wrote:
> > > With the evolving use-cases for TEE bus, now it's required to support
> > > multi-stage enumeration process. But using a simple index doesn't
> > > suffice this requirement and instead leads to duplicate sysfs entries.
> > > So instead switch to use more informative device UUID for sysfs entry
> > > like:
> > > /sys/bus/tee/devices/optee-ta-<uuid>
> > >
> > > Signed-off-by: Maxim Uvarov <maxim.uvarov@linaro.org>
> > > Reviewed-by: Sumit Garg <sumit.garg@linaro.org>
> >
> > Why do you mean by duplicate sysfs entries?
> >
> 
> Without this change it will try to register something like that:
> first stage w/o tee-supplicant:
> /sys/bus/tee/devices/optee-clnt0
> /sys/bus/tee/devices/optee-clnt1
> /sys/bus/tee/devices/optee-clnt3
> Then with tee-supplicant also index started with 0. I.e.
> /sys/bus/tee/devices/optee-clnt0
> /sys/bus/tee/devices/optee-clnt1
> ...
> 
> So we need to increase global index or use some other unique names.

Got it, thanks.

/Jarkko