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Subject: Re: [PATCH v6 32/52] memory: tegra20-emc: Continue probing if timings
 are missing in device-tree
To:     Thierry Reding <thierry.reding@gmail.com>
Cc:     Jonathan Hunter <jonathanh@nvidia.com>,
        Georgi Djakov <georgi.djakov@linaro.org>,
        Rob Herring <robh+dt@kernel.org>,
        Michael Turquette <mturquette@baylibre.com>,
        Stephen Boyd <sboyd@kernel.org>,
        Peter De Schrijver <pdeschrijver@nvidia.com>,
        MyungJoo Ham <myungjoo.ham@samsung.com>,
        Kyungmin Park <kyungmin.park@samsung.com>,
        Chanwoo Choi <cw00.choi@samsung.com>,
        Mikko Perttunen <cyndis@kapsi.fi>,
        Viresh Kumar <vireshk@kernel.org>,
        Peter Geis <pgwipeout@gmail.com>,
        Nicolas Chauvet <kwizart@gmail.com>,
        Krzysztof Kozlowski <krzk@kernel.org>,
        linux-tegra@vger.kernel.org, linux-pm@vger.kernel.org,
        linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
        devicetree@vger.kernel.org
References: <20201025221735.3062-1-digetx@gmail.com>
 <20201025221735.3062-33-digetx@gmail.com> <20201027135244.GM1822510@ulmo>
From:   Dmitry Osipenko <digetx@gmail.com>
Message-ID: <0c306309-6f49-cbac-99ce-6d956d5e910c@gmail.com>
Date:   Tue, 27 Oct 2020 22:38:56 +0300
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27.10.2020 16:52, Thierry Reding пишет:
> On Mon, Oct 26, 2020 at 01:17:15AM +0300, Dmitry Osipenko wrote:
>> EMC driver will become mandatory after turning it into interconnect
>> provider because interconnect users, like display controller driver, will
>> fail to probe using newer device-trees that have interconnect properties.
>> Thus make EMC driver to probe even if timings are missing in device-tree.
> 
> Does it really have to be mandatory? Sounds like that's going to make it
> unnecessarily complicated to merge all of this. Is it complicated to
> make interconnect support optional in consumer drivers?

Interconnect provider can't be optional if interconnect properties
present in a device-tree because drivers that use ICC path will get
-EPROBE_DEFER until ICC provider is registered.

Older device-trees don't have ICC properties, and thus, the ICC
users/consumers will get a dummy NULL ICC path in this case. I.e. ICC
core handles this for us.