From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C5122C531F7 for ; Thu, 23 Jul 2026 20:19:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=46FWN177CCjlOBe+CD5xXNqVAb5ZdbN00qmRFVOXbnw=; b=3/ogmZ2mtoyJxD5LGnxmMb03Qg 4UmRvZ3+NGfd1CzaEcykBDlMhA6O1SbsD0EeOvG5uA3hD9go1zfaSqSMT80Du8rdrmH+9Ox5dpf33 ym3cwZFZMgWBqUtWEPYV4eB/d5BGnKPG7Kc0cTNYPsnCeFkolHwAyMnV2O/yrECqrNL+BCW0PiwYF EAuC0KIka/oFJ2r2C8gy7r1xFyts2d/HFUs+xGzT9Iqrnzejxzcrg9TWJrMts8VtPYHs5eYrnp9sw zkq4aRSrY7n1kvrJWcmivq0Oi+73yBs/nZ4MrSepzmd9sNJXwpZ2/OsQPxDU6yIdGCefwt0Y9GVdo QGXF/tkw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wmzse-0000000F1Pn-1oSL; Thu, 23 Jul 2026 20:18:56 +0000 Received: from leonov.paulk.fr ([185.233.101.22]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wmzsb-0000000F1P7-49AO; Thu, 23 Jul 2026 20:18:55 +0000 Received: from laika.paulk.fr (12.234.24.109.rev.sfr.net [109.24.234.12]) by leonov.paulk.fr (Postfix) with ESMTPS id 46F973700EC1; Thu, 23 Jul 2026 20:18:48 +0000 (UTC) Received: by laika.paulk.fr (Postfix, from userid 65534) id DB8C1B49E9F; Thu, 23 Jul 2026 20:18:46 +0000 (UTC) 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> 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> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260723_131854_356567_BC48B586 X-CRM114-Status: GOOD ( 29.23 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org --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--