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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6E3DDC6FA82 for ; Tue, 13 Sep 2022 12:09:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232007AbiIMMJC (ORCPT ); Tue, 13 Sep 2022 08:09:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35776 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232001AbiIMMJA (ORCPT ); Tue, 13 Sep 2022 08:09:00 -0400 Received: from madras.collabora.co.uk (madras.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e5ab]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A830A5F9B4 for ; Tue, 13 Sep 2022 05:08:59 -0700 (PDT) Received: from [192.168.1.100] (2-237-20-237.ip236.fastwebnet.it [2.237.20.237]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: kholk11) by madras.collabora.co.uk (Postfix) with ESMTPSA id 4649A6602002; Tue, 13 Sep 2022 13:08:57 +0100 (BST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1663070937; bh=ytNEmiOcTsgWo0PMOFDU/i6E5lJKDu8uqwY6x00ydfU=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=bFHlB0J2yobOwBvsWUUS07kgVmtwvhQ8i0BmdU0Mc14MRQ8k2mS60QKiOyPOT4BIm aZrp8CbbkzYxHPK2wQopWJ68KZ0ISvf8ddrLGwPNK4t7Ts336PtSjjQBmSDyZONOF8 Wc+MYU+dWW0Wct9deGcnCiuAa1O3kXKQsBY4fh38B2f88+8SoVJHlQmI3Z1VmN0kYq 9xSorSGxfXLbz3SXAjKJiZ55Hc6yT/JhjPAYyWLK+9LlwHhEmOssamkXBlXswm07dg PRNhCH/5FHNEIb3pY7pY5YNx7zwndByB4z+BDES0tryYxvo7WERu5BVyJY0+1C+WDX ydQ55sH6DQwdA== Message-ID: Date: Tue, 13 Sep 2022 14:08:54 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.2.0 Subject: Re: [PATCH v3] soc: mediatek: Introduce mediatek-regulator-coupler driver Content-Language: en-US To: matthias.bgg@gmail.com Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, wenst@chromium.org, alyssa.rosenzweig@collabora.com, nfraprado@collabora.com, dmitry.osipenko@collabora.com References: <20220628120224.81180-1-angelogioacchino.delregno@collabora.com> From: AngeloGioacchino Del Regno In-Reply-To: <20220628120224.81180-1-angelogioacchino.delregno@collabora.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Il 28/06/22 14:02, AngeloGioacchino Del Regno ha scritto: > This driver currently deals with GPU-SRAM regulator coupling, ensuring > that the SRAM voltage is always between a specific range of distance to > the GPU voltage, depending on the SoC, necessary in order to achieve > system stability across the full range of supported GPU frequencies. > > Signed-off-by: AngeloGioacchino Del Regno > Reviewed-by: Dmitry Osipenko Hello Matthias, gentle ping for this one, as it has been tested for quite a while here, on multiple MediaTek SoCs, and it's working as expected. Can we get it upstream? Is there any blocker? Cheers, Angelo > --- > > Changes in v3: > - Added braces to else-if branch > > Changes in v2: > - Added check for n_coupled > - Added check for vgpu to enforce attaching to vgpu<->sram coupling only > > Context: > This driver is one of the pieces of a bigger puzzle, aiming to finally > enable Dynamic Voltage/Frequency Scaling for Mali GPUs found on MediaTek > SoCs on the fully open source graphics stack (Panfrost driver). > > No devicetree bindings are provided because this does not require any > driver-specific binding at all. > > Last but not least: it was chosen to have this driver enabled for > ( ARCH_MEDIATEK && REGULATOR ) without really giving a free configuration > choice because, once the DVFS mechanism will be fully working, using one > of the listed MediaTek SoCs *without* this coupling mechanism *will* lead > to unstabilities and system crashes. > For COMPILE_TEST, choice is given for obvious reasons. >