Re: [RFC PATCH v2 1/3] drivers/accel: define kconfig and register a new major

From: Jason Gunthorpe <jgg@nvidia.com>
To: Dave Airlie <airlied@gmail.com>
Cc: dri-devel@lists.freedesktop.org,
	Maciej Kwapulinski <maciej.kwapulinski@linux.intel.com>,
	Kevin Hilman <khilman@baylibre.com>,
	Christoph Hellwig <hch@infradead.org>,
	Jagan Teki <jagan@amarulasolutions.com>,
	John Hubbard <jhubbard@nvidia.com>,
	stanislaw.gruszka@intel.com,
	Jeffrey Hugo <quic_jhugo@quicinc.com>,
	Arnd Bergmann <arnd@arndb.de>, Jiho Chu <jiho.chu@samsung.com>,
	Jacek Lawrynowicz <jacek.lawrynowicz@linux.intel.com>,
	Yuji Ishikawa <yuji2.ishikawa@toshiba.co.jp>,
	Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Oded Gabbay <ogabbay@kernel.org>,
	linux-kernel@vger.kernel.org,
	Thomas Zimmermann <tzimmermann@suse.de>,
	Alex Deucher <alexander.deucher@amd.com>
Subject: Re: [RFC PATCH v2 1/3] drivers/accel: define kconfig and register a new major
Date: Tue, 8 Nov 2022 08:28:19 -0400	[thread overview]
Message-ID: <Y2pLYxW8p0QeiV+3@nvidia.com> (raw)
In-Reply-To: <CAPM=9twxu3v4voSukrkror1BrajShRLY9CFxYWpL2rwK7fMiKQ@mail.gmail.com>

On Tue, Nov 08, 2022 at 06:33:23AM +1000, Dave Airlie wrote:

> At plumbers we decided a direction, I think the direction is good, if
> there is refactoring to be done, I'd rather it was done in tree with a
> clear direction.
> 
> Coming in now and saying we should go down a different path isn't
> really helpful. We need to get rolling on this, we have drivers that
> want to land somewhere now, which means we need to just get a
> framework in place, leveraging drm code is the way to do it.

It is not a different path, at plumbers we decided accel should try to
re-use parts of DRM that make sense. I think that should be done by
making those DRM parts into libraries that can be re-used, not by
trying to twist DRM into something weird.

If this thing needs special major/minor numbers, it's own class, its
own debufs, sysfs, etc, then it should not be abusing the DRM struct
device infrastructure to create that very basic kernel infrastructure.

Somehow we ended up with the worst of both worlds. If you want to to
be DRM then it should just be DRM and we shouldn't see all this core
infrastructue code for debugfs/sysfs/cdevs/etc in thes patches at all.

Jason