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 1B18CC00A8F for ; Tue, 24 Oct 2023 09:13:19 +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-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:From:References:Cc:To:Subject: MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=6kncbzLtrhqE/O++lD2VZZeBU24ZZfWM0yZBBuzJ0Ic=; b=Qs9FSFPytlX4tv QBIFeYWjlMHf1Mensn2HMBPFZ+CVMhvbczuR2lF2lfVOHPxYA8w3Mx/WHj2XD4IRQF/llELGO87Zr bmfBVUtVIgJaFBESvrp+0OKqUbp6F6Mwud2Xi8MowogRi6GQugE2lzQtXqlmsZbDvSh9Q5CIJ2t1m 7K+fmCJid16R+y3g87NSwsu23+qKMSpkgaHby1a89CnthQCPJJZAMHhjO4JLwHaQpqhZQ7t4/wh72 /akxVyhPVXNoLDwLXAaZ3kMCu1lgk4J3Ir0BfzN5awPRbNY/zCCFRZr8XnApsS1XN9/rl/Xrc5kBu T6hdALaO2wME22fG5iKQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qvDT4-009HB4-0z; Tue, 24 Oct 2023 09:12:54 +0000 Received: from madras.collabora.co.uk ([46.235.227.172]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qvDT2-009HAd-0A; Tue, 24 Oct 2023 09:12:53 +0000 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 271BE66072F6; Tue, 24 Oct 2023 10:12:48 +0100 (BST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1698138769; bh=XfXPQ0oVnRctPph3CPb1I9j9606bGUTiH9V9O3ZMIGk=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=ZAayU1HWjcx40JeBjgKxWYWr2uAdaRzRDwg9CptGRQK3F8N4pyyUl2MsZhjqgUsQD fhbujYDWpmUiB7lf2ZUIY/Xu5puKX9BnVL5bj/iwpU7ejqKeJGJ6QbSFys85w9jz0Q kbioJO+PH7U7OYD0xsCDzUgpA/uWV4NE9CPdTF02KEEc5cONRV686zrqpC1gL8lZYE zlOo8aeMWJR46gNbtozQval7ZcQpcrrmQFPKf9lg7yH565yJyyiSrBSPtDfYCyKSMu aJN/1EZcPEim62/9Ew16sOnkydctMMXSRwMOtR6x2wlHI2uFOxKc+AJSNUkdG2TM2f 6FrBSYu0Pe33g== Message-ID: Date: Tue, 24 Oct 2023 11:12:45 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 14/18] drm/mediatek: dpi: add support for dpi clock Content-Language: en-US To: amergnat@baylibre.com, Chun-Kuang Hu , Philipp Zabel , David Airlie , Daniel Vetter , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Matthias Brugger , Jitao Shi , Xinlei Lee , CK Hu , Thierry Reding , =?UTF-8?Q?Uwe_Kleine-K=C3=B6nig?= , Catalin Marinas , Will Deacon Cc: dri-devel@lists.freedesktop.org, linux-mediatek@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-pwm@vger.kernel.org, Fabien Parent References: <20231023-display-support-v1-0-5c860ed5c33b@baylibre.com> <20231023-display-support-v1-14-5c860ed5c33b@baylibre.com> From: AngeloGioacchino Del Regno In-Reply-To: <20231023-display-support-v1-14-5c860ed5c33b@baylibre.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231024_021252_238739_64C843E7 X-CRM114-Status: GOOD ( 13.37 ) 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-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Il 23/10/23 16:40, amergnat@baylibre.com ha scritto: > From: Fabien Parent > > MT8365 requires an additional clock for DPI. Add support for that > additional clock. > > Signed-off-by: Fabien Parent > Signed-off-by: Alexandre Mergnat I'm not convinced that this is right... at all. From a fast check of the MT8365 DPI clocks, I can see that the DPI0 clock declares parent VPLL_DPIX (a fixed clock), but nothing ever has VPLL_DPIX_EN (which is the GATE clock, enabling output of DPIx VPLL?). But then, there's even more: no clock ever references the CLK_TOP_DPI0_SEL nor the CLK_TOP_DPI1_SEL gate, which is a PLL parent selector... in other platforms, that is muxing through the TVDPLL, but on MT8365 that is LVDSPLL?! I have many questions now: * Two PLLs are apparently brought up, but which one is the right one?! * Is the LVDS PLL really used for DisplayPort? (dpi0_sel) * Is the VPLL_DPIx PLL used for DisplayPort instead? (dpi0_dpi0) * Why is the LVDSTX_PXL clock using the same PLL as DPI0?! * Why is the VPLL_DPIx gate never enabled? * Are you sure that CLK_MM_DPI0_DPI0's parent shouldn't be dpi0_sel instead? * Where is DPI1 in this SoC? Why is there a dpi1_sel clock, but no MM clock for the DPI1 controller? Is there any DPI1 controller, even?! * Why is there a DPI1 MUX, if there's no DPI1 controller?! Answering all those questions will lead you to the right change, which I believe to be in the clock drivers, not here in mtk_dpi.c. Cheers! Angelo _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel