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From:   John Stultz <john.stultz@linaro.org>
Date:   Thu, 21 Oct 2021 19:56:54 -0700
Message-ID: <CALAqxLXNMvaT3OU3Y-aYkH+KJA_g1QSOZNJHqvzt21WPy=6UJw@mail.gmail.com>
Subject: Re: [PATCH v2] dma-buf: heaps: init heaps in subsys_initcall
To:     Shuosheng Huang <huangshuosheng@allwinnertech.com>
Cc:     Sumit Semwal <sumit.semwal@linaro.org>,
        Liam Mark <lmark@codeaurora.org>,
        Laura Abbott <labbott@redhat.com>,
        Brian Starkey <Brian.Starkey@arm.com>,
        Christian Koenig <christian.koenig@amd.com>,
        linux-media <linux-media@vger.kernel.org>,
        dri-devel <dri-devel@lists.freedesktop.org>,
        lkml <linux-kernel@vger.kernel.org>
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On Thu, Oct 21, 2021 at 6:49 PM Shuosheng Huang
<huangshuosheng@allwinnertech.com> wrote:
>
> Some built-in modules will failed to use dma-buf heap to allocate
> memory if the heap drivers are too late to be initialized.
> To fix this issue, move initialization of dma-buf heap drivers in
> subsys_initcall() which is more earlier to be called.

Hey! Thanks so much for sending this out! I appreciate it!

So the change looks pretty straightforward to me, however, the
rationale for it is where we hit problems.

With the upstream kernel, there are not yet any modules that directly
allocate from dmabuf heaps. So in the context of the upstream kernel,
the reasoning doesn't make much sense.

Now, I know folks have their own drivers that want to allocate from
dmabuf heaps, but those haven't been submitted upstream yet.
So maybe can you submit those patches that need this along with this
change so it would make sense as part of a patch series? It would be
trivial to justify including this patch then.

thanks
-john