From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.steuer-voss.de (mail.steuer-voss.de [85.183.69.95]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3EF461AC444 for ; Mon, 2 Dec 2024 17:03:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=85.183.69.95 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733159006; cv=none; b=FGKkNlho8GvKxDIfNWNx1cQW6ldZglk3BTU4yBRJE2VqAjhgfyquYD31Ir3s4XLarqTnQsmG5q3qvSNDoaJd10nvmUoOxyEHv1bH0OLKxsIN9rGp7O42hQD8PWkig7pUTt28iw7sRfv4Y1x+KVbyQZjpSuJzLHE9B5vLblyGEao= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733159006; c=relaxed/simple; bh=UraHYu3PVGdBa1G5kKPcqpScOE2DGLtNUyGJsKgIW1I=; h=MIME-Version:Date:From:To:Cc:Subject:In-Reply-To:References: Message-ID:Content-Type; b=BqEJrgsPimcT4xunrloL8oT1HMJYknZZvlyWJRn6DV44mKEH8f6UVtg3VKxKzo7tOeGCm0rFNSB2FzFSDnaihQyr3s7PDPAgt8QbL6tXQy5l0HWmwjX/HNiT/FU7UZgctnnVYRpg5XgqaCfsvsunW9pDf56YRcrlTj1Ket+YZLo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=vosn.de; spf=pass smtp.mailfrom=vosn.de; arc=none smtp.client-ip=85.183.69.95 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=vosn.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=vosn.de X-Virus-Scanned: Debian amavisd-new at mail.steuer-voss.de Received: from mail.steuer-voss.de (localhost [127.0.0.1]) by mail.steuer-voss.de (Postfix) with ESMTP id AA1BB2D2; Mon, 2 Dec 2024 18:03:16 +0100 (CET) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Date: Mon, 02 Dec 2024 18:03:16 +0100 From: Nikolaus Voss To: Marek Vasut Cc: Liu Ying , Alexander Stein , Liu Ying , Luca Ceresoli , Fabio Estevam , Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , David Airlie , Daniel Vetter , Miquel Raynal , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, nikolaus.voss@haag-streit.com Subject: Re: [PATCH] drm: bridge: fsl-ldb: fixup mode on freq mismatch In-Reply-To: <50ee0207-b37a-4a6a-83fe-32a7a43645ce@denx.de> References: <20241126172610.AD8B51622C@mail.steuer-voss.de> <1f0a307a-666f-4647-9f73-e9bddd6c7eff@oss.nxp.com> <50ee0207-b37a-4a6a-83fe-32a7a43645ce@denx.de> User-Agent: Roundcube Webmail/1.5.0 Message-ID: <9cc55af202690bad0616bee76430133d@vosn.de> X-Sender: nv@vosn.de Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit On 02.12.2024 13:56, Marek Vasut wrote: > On 12/2/24 7:32 AM, Liu Ying wrote: >> On 11/27/2024, Nikolaus Voss wrote: >>> LDB clock has to be a fixed multiple of the pixel clock. >>> As LDB and pixel clock are derived from different clock sources >>> (at least on imx8mp), this constraint cannot be satisfied for >>> any pixel clock, which leads to flickering and incomplete >>> lines on the attached display. >>> >>> To overcome this, check this condition in mode_fixup() and >>> adapt the pixel clock accordingly. >>> >>> Cc: >> >> It looks like stable is not effectively Cc'ed. >> Need a Fixes tag? > Isn't this fix effectively superseded by series > > [PATCH 0/5] clk: Fix simple video pipelines on i.MX8 > > ? Maybe. I wasn't aware of the series. Looking at it, the change is rather complex and not suitable for the stable series. My intention was to get a simple fix which doesn't potentially break anything. It wouldn't even break the patch series you mentioned. -- Nikolaus Voss