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 5F082C433F5 for ; Fri, 14 Jan 2022 13:49:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=6/hltuajLwy2e6MdBe4RmXKDbc/0fm43XDcrErx8V3o=; b=ZW1JG9DD6xVc1U WPFWwL8Us+wqlIe9xblhSMA+ly2bxR3t/PXNLx53eHHngIFDGlo6GxuUQVG1IbczUBYrgry+pMh5K 8PDJwR7fFuQpplnTaRp04prrA/r7e9BxS9a+ULxK1oBygrFHJGW7hbKb2jUcKSHZD6Gc0bpaF1fhG J3eVC0NrvIdHhcsFHgXtc/DqX0LK7Uk6H3QWpZBfWfGpJANR4oNGxqC/H3ebgGw0EhQu003kK6jzq GWkdVYhzmNqtYzkkjvscdUDU9FuhtoeM38Ih7/rxt4wOq9NU1Ulkt5Qn+BHZyLuvVLUWP7B+Tteuc 5s4CQijh09tN/q4GA6fg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1n8Mvz-009FYO-L4; Fri, 14 Jan 2022 13:48:03 +0000 Received: from bhuna.collabora.co.uk ([46.235.227.227]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1n8Mvu-009FX9-CG; Fri, 14 Jan 2022 13:48:01 +0000 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: alyssa) with ESMTPSA id 870631F469D3 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1642168074; bh=mPZukNT2prSJfKzrqXnhU1Wq/pLiKiBo5wzaQ4Cxjrs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Jw1sK7HFZJ3M7Q21H7avJs9Bw2IwAY3ZxCrpoXlhn4iB6+daUb0UauvXwDDQmyqh9 5jaTw34G3FoOAwtb9eYmS/u9CcKxznoTEmeWdCXmuANwlgs5NueCWCU7s40RRKjklR CSPY09G7TP2W15Uo/L6qvMjSkyAvr29k3Xl2GzW/yCmWL+6TipNSxLC1BG7xMjWoFP FCKTGkLkVt0w92yHmKEDEVI4mhQfyGUp7ardEB4PqD3dbQ7XuKR50/pYv6RWM2odXs oPa4fxj5mDqEvyRirVigsyYCLAnS8GROYQgzJGNegYuLJ6SjnLGvPxOCFFNrlPJbYw uDEQ5xDbkcLrw== Date: Fri, 14 Jan 2022 08:47:45 -0500 From: Alyssa Rosenzweig To: Robin Murphy Cc: Alyssa Rosenzweig , linux-mediatek@lists.infradead.org, Michael Turquette , Stephen Boyd , Matthias Brugger , Ikjoon Jang , Chun-Jie Chen , Weiyi Lu , linux-clk@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Nick Fan , Nicolas Boichat Subject: Re: [PATCH] clk: mediatek: Disable ACP to fix 3D on MT8192 Message-ID: References: <20220110181330.3224-1-alyssa.rosenzweig@collabora.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220114_054758_601500_62E9199E X-CRM114-Status: GOOD ( 16.86 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org > > That links to an internal Google issue tracker which I assume has more > > information on the bug. I would appreciate if someone from Google or > > MediaTek could explain what this change actually does and why it's > > necessary on MT8192. > > > > At any rate, this register logically belongs to the MT8192 "infra" clock > > device, so it makes sense to set it there too. This avoids adding any > > platform-specific hacks to the 3D driver, either mainline (Panfrost) or > > legacy (kbase). > > Does this really have anything to do with clocks? I have no idea. MediaTek, Google, please explain. > In particular, "ACP" usually refers to the Accelerator Coherency Port > of a CPU cluster or DSU, and given the stated symptom of the issue > affected by it, my first guess would be that this bit might indeed > control routing of GPU traffic either to the ACP or the (presumably > non-coherent) main interconnect. I'd easily believe that. > If that is the case, I think this would logically belong as a SoC-specific > quirk in panfrost, where we'd need to retrieve the syscon regmap for > ourselves (see around line 800 of drivers/iommu/mtk_iommu.c for a similar > example). Alright. Doing this in panfrost seems ugly but if that's the right place for it, that's the right place for it. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel