From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2A8A8606A31A for ; Thu, 29 Oct 2026 09:50:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=NlG35jxV Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 7C64611213F; Thu, 29 Oct 2026 09:50:01 +0000 (UTC) Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by gabe.freedesktop.org (Postfix) with ESMTPS id 80EC4112155 for ; Thu, 29 Oct 2026 09:49:55 +0000 (UTC) Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 3631341422; Thu, 29 Oct 2026 09:49:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1E53B1F01825; Thu, 29 Oct 2026 09:49:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793267395; bh=f5wVeAcdts4v03FIKJ/JOAEQfcFu0V9y5FXGBERX1Fw=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=NlG35jxV24Z1YixSeCYzFE3xFG+HNtJK13nn+Ycyx9xJlAOucFuA/+KyKql9//itR piKf0GUZxb5qfLhw9ewcnJ81lVksGPJpIdC/IFnaVkQ5jn34zDqk15ECcuFxFBhRkx k0yy6RP/HkVb78tRMXKKM5d08T9SoOLsHHbHWLTCM3Jo5ZUfwnG6V0akNiP5LIAOsc l0D9um68z0c6D9snkZAulc1qCyBCt6v/T7gXwwMoth+wi1XgpHfZ4RmiFNdrxcvBpL 3IJ+syhvaQlZxOW4XMezuEm6cb/a6hY9TrZnWFn/l5dcqFNyWs6tLe3iMYG4aXaGXd CxbR9rCboLzpw== Date: Thu, 29 Oct 2026 10:49:51 +0100 From: Krzysztof Kozlowski To: Vladimir Zapolskiy Cc: Neil Armstrong , Jessica Zhang , Ritesh Kumar , Rob Herring , Krzysztof Kozlowski , Bjorn Andersson , Konrad Dybcio , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , dri-devel@lists.freedesktop.org, Conor Dooley , devicetree@vger.kernel.org, Abel Vesa , linux-arm-msm@vger.kernel.org Subject: Re: [PATCH 1/8] dt-bindings: display: panel: novatek,nt36672e: Document the reset GPIO polarity Message-ID: <20261029-calculating-imaginary-wolf-ccb2a2@quoll> References: <20261028095151.1682096-1-vz@kernel.org> <20261028095151.1682096-2-vz@kernel.org> <20261028-seagull-of-illegal-prestige-6cbbfa@quoll> <07c2c10c-f442-480d-b545-666069c06e91@kernel.org> <61e36fb1-6959-4c69-9afb-53264ff9331d@kernel.org> X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "dri-devel" X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On Wed, Oct 28, 2026 at 10:27:35PM +0200, Vladimir Zapolskiy wrote: > On 10/28/26 16:59, Krzysztof Kozlowski wrote: > > On 28/10/2026 15:56, Vladimir Zapolskiy wrote: > > > > We might fix it at some point, so not sure if it is worth documenting in > > > > the binding. And what about usage of this binding in other projects > > > > which implement it correctly? > > > > > > > > > > In the upstream there is only one user qcm6490-idp.dts, and changing > > > the polarity will be an ABI breaking change, unfortunately. > > > > And all other projects? > > > > It might be a challenging task to check usage of "novatek,nt36672e" > compatible display panels in all other projects. I've asked about it: > > * https://chatgpt.com/uc/6ae25571-2ef0-83ea-81e5-2522e70c4a93 > > The check gives this info: > > 1. Linux kernel - invalid GPIO polarity in the driver and qcm6490-idp.dts, > 2. Android - invalid GPIO polarity in the copied driver and qcm6490-idp.dts, > 3. FreeBSD - invalid GPIO polarity in the copied qcm6490-idp.dts, no driver. > > Please let me know, if there are other projects to check. To my > understanding the RESET_N polarity cannot be corrected anymore, > and the best option is to clearly document a difference between > the device and its dt-binding documentation. It can be correct, just with impact so we choose not to, but nevertheless hardware wants different polarity, so you should not state in the binding the incorrect one. This property corresponds to the hardware, not chosen SW implementation. Best regards, Krzysztof