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Date:   Tue, 25 Oct 2022 08:15:16 -0300
From:   Jason Gunthorpe <jgg@nvidia.com>
To:     Dave Airlie <airlied@gmail.com>
Cc:     John Hubbard <jhubbard@nvidia.com>,
        Oded Gabbay <ogabbay@kernel.org>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        Daniel Vetter <daniel@ffwll.ch>, Arnd Bergmann <arnd@arndb.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
        Alex Deucher <alexander.deucher@amd.com>,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Maxime Ripard <mripard@kernel.org>,
        Yuji Ishikawa <yuji2.ishikawa@toshiba.co.jp>,
        Jiho Chu <jiho.chu@samsung.com>,
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        Jagan Teki <jagan@amarulasolutions.com>,
        Jacek Lawrynowicz <jacek.lawrynowicz@linux.intel.com>,
        Maciej Kwapulinski <maciej.kwapulinski@linux.intel.com>
Subject: Re: [RFC PATCH 0/3] new subsystem for compute accelerator devices
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On Tue, Oct 25, 2022 at 12:27:11PM +1000, Dave Airlie wrote:

> The userspace for those is normally bespoke like ROCm, which uses
> amdkfd, and amdkfd doesn't operate like most device files from what I
> know, so I'm not sure we'd want it to operate as an accel device.

I intensely dislike this direction that drivers will create their own
char devs buried inside their device driver with no support or
supervision.

We've been here before with RDMA and it is just a complete mess.

Whatever special non-drm stuff amdkfd need to do should be supported
through the new subsystem, in a proper maintainable way.

Jason