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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 AFCC9C433EF for ; Wed, 22 Dec 2021 19:40:05 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 901E610E1A7; Wed, 22 Dec 2021 19:40:04 +0000 (UTC) Received: from gloria.sntech.de (gloria.sntech.de [185.11.138.130]) by gabe.freedesktop.org (Postfix) with ESMTPS id 0994510E27B for ; Wed, 22 Dec 2021 19:40:04 +0000 (UTC) Received: from ip5b412258.dynamic.kabel-deutschland.de ([91.65.34.88] helo=diego.localnet) by gloria.sntech.de with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1n07Sx-00053n-LH; Wed, 22 Dec 2021 20:39:59 +0100 From: Heiko =?ISO-8859-1?Q?St=FCbner?= To: Sascha Hauer , Rob Herring Subject: Re: [PATCH 08/22] dt-bindings: display: rockchip: dw-hdmi: use "ref" as clock name Date: Wed, 22 Dec 2021 20:39:58 +0100 Message-ID: <8156864.jFcTpQmkuZ@diego> In-Reply-To: References: <20211220110630.3521121-1-s.hauer@pengutronix.de> <20211222104736.GZ6003@pengutronix.de> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: devicetree@vger.kernel.org, Benjamin Gaignard , Peter Geis , Sandy Huang , dri-devel , "open list:ARM/Rockchip SoC..." , Michael Riesch , Sascha Hauer , Andy Yan , linux-arm-kernel Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Am Mittwoch, 22. Dezember 2021, 14:52:51 CET schrieb Rob Herring: > On Wed, Dec 22, 2021 at 6:47 AM Sascha Hauer wrote: > > > > On Tue, Dec 21, 2021 at 10:31:23AM -0400, Rob Herring wrote: > > > On Mon, Dec 20, 2021 at 12:06:16PM +0100, Sascha Hauer wrote: > > > > "vpll" is a misnomer. A clock input to a device should be named after > > > > the usage in the device, not after the clock that drives it. On the > > > > rk3568 the same clock is driven by the HPLL. > > > > To fix that, this patch renames the vpll clock to ref clock. > > > > > > The problem with this series is it breaks an old kernel with new dt. You > > > can partially mitigate that with stable kernel backport, but IMO keeping > > > the old name is not a burden to maintain. > > > > As suggested I only removed vpll from the binding document, but not from > > the code. The code still handles the old binding as well. > > The problem is updating rk3399.dtsi. That change won't work with old > kernels because they won't look for 'ref'. Since you shouldn't change > it, the binding needs to cover both the old and new cases. is "newer dt with old kernel" really a case these days? I do understand the new kernel old dt case - for example with the dtb being provided by firmware. But which user would get the idea of updating only the devicetree while staying with an older kernel?