From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from phobos.denx.de (phobos.denx.de [85.214.62.61]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A26851A724C; Sat, 23 Nov 2024 22:34:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=85.214.62.61 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732401281; cv=none; b=Uvve43jZu2qrp0CQTlBfFfkFItRa5Te6RQ5Tyr0VwnwgIn/scRudNBWdPAYjrsxiylMFx6qa8oPpcDSGPeYg5/P+s4d8ay3to5z81zeDQGfqtQ/uVss3n0/W6Ggd9+xdC5KnQ6AbvyQYpp6bYRGZ58gtKRttbhRYWnxa92ZrdwM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732401281; c=relaxed/simple; bh=vIqWvHz/juZcLWbUqjLSwK38ndJaU0c4olpBuC7k//M=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=FW5y+SfyObleo+hMGZOh4mBXIEufehbzGxkk6FCjVPnA3wUCUwZnLmDvGfljKjuj+xJ/VdHW7Lrs8cqkxFqzrXNWocCnizhjE31ikVPbnRJtcVoCGWcpCzalTogk1w7w0ZthGZaY2kURXLS4U0qebi0I6IgXGXzbVXwtPr4ub2Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=denx.de; spf=pass smtp.mailfrom=denx.de; dkim=pass (2048-bit key) header.d=denx.de header.i=@denx.de header.b=cYxJwfmT; arc=none smtp.client-ip=85.214.62.61 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=denx.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=denx.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=denx.de header.i=@denx.de header.b="cYxJwfmT" Received: from [127.0.0.1] (p578adb1c.dip0.t-ipconnect.de [87.138.219.28]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: marex@denx.de) by phobos.denx.de (Postfix) with ESMTPSA id 944DD89401; Sat, 23 Nov 2024 23:34:25 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=denx.de; s=phobos-20191101; t=1732401268; bh=UVI84fOke9gLRZ0suzoYkdmP/Z7GYELBjts2k6DzJl0=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=cYxJwfmTaViuJOl0E6LpQm/Yli1C/FbRzss9eticyEKW0qVpN1ZSjg/mt+Jhflech xZPDZK/2aDIWkoZCayi0JfCMpOWINUNWavA6h3p2lCt5sGaekQVrM1Rh3lMJzDDT9I 0P5uEXc/IOYzu8lRmA7IUMCIbDIOfeYVkTgl43z8X46shVEBMmRvaPIOo39o0Smn2y MzUfd3fB98Nx4L29dvoE4Wub78AS+8by0lY2Ld8CUxGFA2OhGcx/7eFtjUcbUiFYI6 UDMn/y70IKCsE1VZzCaAq9TgOEH8XdQr2XrBNHm4cLfehwhtgt2Hdz4lEZNyzoctiu 1lij3zQXXUpgw== Message-ID: Date: Sat, 23 Nov 2024 21:11:58 +0100 Precedence: bulk X-Mailing-List: linux-clk@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v7 2/7] Revert "clk: imx: clk-imx8mp: Allow media_disp pixel clock reconfigure parent rate" To: Ying Liu , "imx@lists.linux.dev" , "linux-arm-kernel@lists.infradead.org" , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-clk@vger.kernel.org" , "dri-devel@lists.freedesktop.org" Cc: "shawnguo@kernel.org" , "s.hauer@pengutronix.de" , "kernel@pengutronix.de" , "festevam@gmail.com" , "robh@kernel.org" , "krzk+dt@kernel.org" , "conor+dt@kernel.org" , "catalin.marinas@arm.com" , "will@kernel.org" , "abelvesa@kernel.org" , Peng Fan , "mturquette@baylibre.com" , "sboyd@kernel.org" , "andrzej.hajda@intel.com" , "neil.armstrong@linaro.org" , "rfoss@kernel.org" , Laurent Pinchart , "jonas@kwiboo.se" , "jernej.skrabec@gmail.com" , "maarten.lankhorst@linux.intel.com" , "mripard@kernel.org" , "tzimmermann@suse.de" , "airlied@gmail.com" , "simona@ffwll.ch" , "quic_bjorande@quicinc.com" , "geert+renesas@glider.be" , "dmitry.baryshkov@linaro.org" , "arnd@arndb.de" , "nfraprado@collabora.com" , Luca Ceresoli , Miquel Raynal References: <20241114065759.3341908-1-victor.liu@nxp.com> <20241114065759.3341908-3-victor.liu@nxp.com> <8a4fd234-4c7b-4a04-990d-3222aaa5172d@denx.de> <83be0a27-6b6c-4ba6-b9dc-f914a10abace@denx.de> Content-Language: en-US From: Marek Vasut In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: clamav-milter 0.103.8 at phobos.denx.de X-Virus-Status: Clean On 11/22/24 4:39 AM, Ying Liu wrote: > On 11/22/24, Marek Vasut wrote: >> On 11/20/24 7:38 AM, Ying Liu wrote: >> >> [...] >> >>>>> If the DP monitors support typical video modes like 1080p60 with >>>>> 148.5MHz pixel clock rate, I assume these typical video modes work >>>>> still ok with this patch at least. Please help confirm this, since if the >>>>> alternative solution(*) doesn't stand, we would know those video >>>>> modes still work ok with my solution(fixed PLL rate). >>>> >>>> They do not work with the fixed PLL setting. >>> >>> Why? Did you assign a sensible fixed PLL rate in DT? >> >> Whatever was in imx8mp.dtsi does not really work for all the panels. >> Please keep in mind that the use case I have does not include only >> 1920x1080 "standard" panels, but also other resolutions. > > It looks like you are still sticking to the idea of supporting all potentially > valid video modes by trying to find an "alternative" solution, while > neglecting that the solution *could be* never working. Reconfiguring the PLL to achieve accurate pixel clock is working already, right now. >>> Can you please compare clk_summary output for the failing cases >>> before and after this patch is applied? I assume that if you use >>> the fixed PLL rate same to the rate which works before this patch is >>> applied, the typical video modes still just work after this patch is >>> applied. >> >> I'm afraid I do not need to support only typical video modes, but also >> the other "atypical" modes. > > If the "alternative" solution doesn't work, we'll end up using the "fixed > PLL rate" solution. It that case, some video modes would be filtered > out as a sacrifice. Maybe it would be better to continue the discussion in [PATCH 0/5] clk: Fix simple video pipelines on i.MX8 which seems close to the alternative solution I was looking for ?