linux-kernel - Re: [PATCH v6 7/9] media: mtk-mdp: use mdp-rdma0 alias to point to MDP master

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAOak1e-oyzxbvHimMReQpZCAPyCtAsaGixjwmoa0EzMjqaUxVg@mail.gmail.com>
Date:   Wed, 18 Aug 2021 17:43:33 +1000
From:   Eizan Miyamoto <eizan@...omium.org>
To:     houlong wei <houlong.wei@...iatek.com>
Cc:     "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "wenst@...omium.org" <wenst@...omium.org>,
        Yong Wu (吴勇) <yong.wu@...iatek.com>,
        "enric.balletbo@...labora.com" <enric.balletbo@...labora.com>,
        "devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
        "chunkuang.hu@...nel.org" <chunkuang.hu@...nel.org>,
        Andrew-CT Chen (陳智迪) 
        <andrew-ct.chen@...iatek.com>,
        Matthias Brugger <matthias.bgg@...il.com>,
        Mauro Carvalho Chehab <mchehab@...nel.org>,
        Minghsiu Tsai (蔡明修) 
        <minghsiu.tsai@...iatek.com>,
        "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>,
        "linux-media@...r.kernel.org" <linux-media@...r.kernel.org>,
        "linux-mediatek@...ts.infradead.org" 
        <linux-mediatek@...ts.infradead.org>
Subject: Re: [PATCH v6 7/9] media: mtk-mdp: use mdp-rdma0 alias to point to
 MDP master

Hi Houlong,

On Mon, Aug 16, 2021 at 1:00 PM houlong wei <houlong.wei@...iatek.com> wrote:
> Hi Eizan,
>
> "mdp-rdma0" may be not the only one master device node. In fact, there
> are 2 "mdp-rdma" in mt8173. You can see "mdp_rdma1" via below link.
>
> https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/arch/arm64/boot/dts/mediatek/mt8173.dtsi?h=v5.13.11#n1016
> If we add "mediatek,mt8173-mdp" to "mdp_rdma1" like below, we will have
> one more V4L2 video devie node.
>
>                 mdp_rdma1: rdma@...02000 {
>                         compatible = "mediatek,mt8173-mdp-rdma",
>                                      "mediatek,mt8173-mdp";
>                         ...
>                 }
>
> We should consider the case that there are more than one "MDP_RDMA"
> components.

Would it be okay with you if we added support for multiple MDP master
device nodes in follow-up changes? My rationale is this:
- As far as I can tell, the mediatek integration with V4L2 currently
only handles a single MDP master device node. It's not clear to me the
scope of changes that will be needed to make things work properly with
multiple nodes.
- The patch series makes video decode work (admittedly, in light of
your comments not optimally) upstream, which is better than not
landing these changes at all.

I'd like to say that I'm very open to (and excited about) discussing
further work to support multiple MDP master nodes, perhaps we can
work together on this so I can understand what needs to be done.

Please let me know your thoughts,

Eizan