From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from leonov.paulk.fr (leonov.paulk.fr [185.233.101.22]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 353773EFFD1; Thu, 23 Jul 2026 20:18:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.233.101.22 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784837955; cv=none; b=SkYsIPamw5SHhvjWTP43T8QrWK6edfixmHxKnYzweLRrY0HPehxah2zi4u4EXUemrJvuAPX+ABobNAfn/LrA1fxavFYHpMjBVWbllsgQ8X1c6sxy/UTbdBoNhFuuGVSTZESWPYKkqxwftvvXqu1FyX+OGDESTsbRNJ1zg/vKA9s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784837955; c=relaxed/simple; bh=46FWN177CCjlOBe+CD5xXNqVAb5ZdbN00qmRFVOXbnw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ZmGzktfgSI3dL7mr7ueYxjdfDWdj6z55/d2pWHlYXczipOh//BveTiqxoL9CGyhpmIDDZk9bhLWUiqStngvmOrRCibBrUtw0/Lke/li5hXXYBVvOwLgkAPvWId8mCily57mlFlGlwpYoSqKFzurZMrOczMZ1ZK5o0Key3oca68Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sys-base.io; spf=pass smtp.mailfrom=sys-base.io; arc=none smtp.client-ip=185.233.101.22 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sys-base.io Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sys-base.io Received: from laika.paulk.fr (12.234.24.109.rev.sfr.net [109.24.234.12]) by leonov.paulk.fr (Postfix) with ESMTPS id E587A3700EC4; Thu, 23 Jul 2026 20:18:48 +0000 (UTC) Received: by laika.paulk.fr (Postfix, from userid 65534) id 283A5B49EA2; Thu, 23 Jul 2026 20:18:47 +0000 (UTC) X-Spam-Level: Received: from collins (unknown [192.168.1.1]) by laika.paulk.fr (Postfix) with ESMTPSA id C5575B49E99; Thu, 23 Jul 2026 20:18:45 +0000 (UTC) Date: Thu, 23 Jul 2026 22:18:44 +0200 From: Paul Kocialkowski To: Nicolas Dufresne Cc: Jiaxing Hu , detlev.casanova@collabora.com, mchehab@kernel.org, heiko@sntech.de, robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, ezequiel@vanguardiasur.com.ar, linux-media@vger.kernel.org, devicetree@vger.kernel.org, linux-rockchip@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH 0/3] media: rockchip: VEPU510 H.264 encoder for RK3576 Message-ID: References: <20260722073417.2064667-1-gahing@gahingwoo.com> <082e1141c38205222a91abf13b1a97d9a00e117a.camel@collabora.com> <20260723004642.2075233-1-gahing@gahingwoo.com> <210b72e32d1bd757a36b2baf532dd9f7d46ca5dc.camel@collabora.com> <252d53c9e497530f9416599f9991b02c0c276a1f.camel@collabora.com> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="5NbzU9qqaTRP7CtZ" Content-Disposition: inline In-Reply-To: <252d53c9e497530f9416599f9991b02c0c276a1f.camel@collabora.com> --5NbzU9qqaTRP7CtZ Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi Nicolas, Le Thu 23 Jul 26, 15:39, Nicolas Dufresne a =C3=A9crit : > Hi Paul. >=20 > Le jeudi 23 juillet 2026 =C3=A0 20:41 +0200, Paul Kocialkowski a =C3=A9cr= it=C2=A0: > > In my opinion it would be fine to have two drivers, but it's really up > > to you. Since you already have a v4l2 base for it, I would encourage you > > to move it to my proposal, which will probably be finalized in a shorter > > time frame than the other proposal and lets you reuse the code you've > > already written. Then you could also add RK3576 support to the drm-ish > > Vulkan Video proposal without too much work when it is ready, reusing t= he > > RK3588 work. >=20 > My main concern is that once you exposed an API, the transition path is n= ear > impossible unless you accept to support both APIs concurrently. So I may = raise a > slight objection on the above proposal. Well there could be a recommended implementation using your design and a more experimental v4l2 implementation that is discouraged to use but still available. But that means another driver to maintain and more long-term involvement =66rom Jiaxing Hu. I am not sure it is worth it, but I don't think we should entirely close the door on the idea. I also understand that there can be a bit of frustration with trashing code and a desire to continue working on it (especially now that it can benefit from the technical knowledge acquired from your work). But I'm just speculating here. Still I would be interested to eventually be able to compare performance between the two approaches on the same hardware :) > Once we have the code shared (Detlev is > working on it), you'll see that Detlev (and Daniel Almeida) implementatio= n is > just a step ahead, and adding RK3576 to an RK3588 is just a minor update = (its > the same chip, different minor version). On top of which, once the kernel= driver > will have settled, adding more codecs will mostly (or entirely) happen in > userspace. >=20 > With no offense, the RFC here requires significant work before it can be > upstreamed. A lot of the code is hex tables generated from inspecting a r= unning > driver. So there is a lot of work to decipher this into clean code. Yes I'm sure there is still a lot of work to do. All the best, Paul > On that aspect, if you are missing any reference code or technical > documentation, let us know, though I believe most of this is public infor= mation > for this chip. >=20 > regards, > Nicolas --=20 Paul Kocialkowski, Independent contractor - sys-base - https://www.sys-base.io/ Free software developer - https://www.paulk.fr/ Expert in multimedia, graphics and embedded hardware support with Linux. --5NbzU9qqaTRP7CtZ Content-Type: application/pgp-signature; name=signature.asc -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEEAbcMXZQMtj1fphLChP3B6o/ulQwFAmpidyQACgkQhP3B6o/u lQxJyQ//UloJz5n2lXdGyt3Z62A+B4oIbB2DTJ/v3EPlh37fTfmMOnXOR25G/Em+ I/4rc0DjJmSROIwu4b8DnZ5VC3NVG/K1F1+MxV67UXImGveKxrKzzs8CJ5/7GoOB Gb8Xm6XzGYgsT+gYuNq5pxSIOZkO5RjrXlZdXGY1kkCO+0ht4ZBOZgSHWktIYWva 1wLIDQkt+eHnQ26lVLs1bDFjy8zE3UZXYTC04Qx/P0RNMA59f0iajMuVEOR9smvA DqDQV7kklKA6wwqXYY4ksgDdIdyYuJVSLrBYMAIuS0CcGQEKkc3nB841bRT2Ow6y ll8iHyq2ACkhJMZbG5uZ8W4258sLZ7Cp1bCAlK4dWwM9e0CArnqAdP7Y8g1RBfMn ydWXbCl5wKIr1tQOTXDlu+pH+3k1lXj11FBi8zlB3CqwaFIibx9zTy3gAapzPJX5 ZHLw8t7dcK8xpaHAJXb0iDuffX+iOoa1irhTt9WCgfkZhOaPyh529N9GVHm1l54N pLWa3cw4IkJ4n2HuKPnzkB/2sJrY/l7cng9yQH7+ls/7Weq5x/R4qMJCKOCu42GX tpU5Dv13enniO8YpCbm94KetXN1OqLlC259A71vC9MlalzSmyGYr/RL8RICQ0+9O kHxrS0Syc2qOjAfePLfm2KAMwbvsJ0K8iLN5wvSUa3gLnIkpJSc= =Nec2 -----END PGP SIGNATURE----- --5NbzU9qqaTRP7CtZ--