Subject: Re: [PATCH v4 2/2] staging: ion: create one device entry per heap
To: Mark Brown <broonie@kernel.org>,
        Benjamin Gaignard <benjamin.gaignard@linaro.org>
Cc: sumit.semwal@linaro.org, gregkh@linuxfoundation.org, arve@android.com,
        riandrews@android.com, dan.carpenter@oracle.com,
        devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org,
        dri-devel@lists.freedesktop.org, linux-api@vger.kernel.org
References: <1506427625-19202-1-git-send-email-benjamin.gaignard@linaro.org>
 <1506427625-19202-3-git-send-email-benjamin.gaignard@linaro.org>
 <20170926161701.aegnk3kb3fpgz4uy@sirena.org.uk>
From: Laura Abbott <labbott@redhat.com>
Message-ID: <adcb091c-ce01-1e04-2cc2-8c36f67433f3@redhat.com>
Date: Tue, 26 Sep 2017 11:08:34 -0700
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On 09/26/2017 09:17 AM, Mark Brown wrote:
> On Tue, Sep 26, 2017 at 02:07:05PM +0200, Benjamin Gaignard wrote:
> 
>> version 4:
>> - add a configuration flag to switch between legacy Ion misc device
>>    and one device per heap version.
> 
> Should this be a switch or should it just be enabling and disabling the
> legacy device with the per heap ones always availalbe?  I can't see that
> the new devices would do any harm or have trouble interacting with the
> per heap ones.  Being able to have both enabled would make things easier
> for userspaces that are moving to the device per heap interface.
> 

Agreed. We should be enabling the new interface unconditionally. The
old /dev/ion interface should coexist to allow for backwards
compatibility but keep it under a Kconfig to allow it to be turned off
for security or other reasons.

Thanks,
Laura