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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 79E581098783 for ; Fri, 20 Mar 2026 13:20:23 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id DE75E10E1EE; Fri, 20 Mar 2026 13:20:22 +0000 (UTC) Received: from ni.piap.pl (ni.piap.pl [195.187.100.5]) by gabe.freedesktop.org (Postfix) with ESMTPS id A488D10E1EE for ; Fri, 20 Mar 2026 13:20:20 +0000 (UTC) Received: from t19.piap.pl (OSB1819.piap.pl [10.0.9.19]) by ni.piap.pl (Postfix) with ESMTPS id 655BEC3EEAC9; Fri, 20 Mar 2026 14:20:16 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 ni.piap.pl 655BEC3EEAC9 From: =?utf-8?Q?Krzysztof_Ha=C5=82asa?= To: Maxime Ripard Cc: Marco Felsch , Marek Vasut , Stefan Agner , Liu Ying , Simona Vetter , imx@lists.linux.dev, Fabio Estevam , Pengutronix Kernel Team , Maarten Lankhorst , Sascha Hauer , Frank Li , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Thomas Zimmermann , David Airlie , linux-arm-kernel@lists.infradead.org Subject: Re: i.MX8MP: Fix HDMI LCDIF FIFO underruns In-Reply-To: <20260320-amiable-hairy-bullfinch-28bfda@houat> (Maxime Ripard's message of "Fri, 20 Mar 2026 10:25:11 +0100") References: <32317022-3c44-4ead-9e2d-04caa12b28cb@nabladev.com> <20260320-amiable-hairy-bullfinch-28bfda@houat> Date: Fri, 20 Mar 2026 14:20:15 +0100 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Maxime Ripard writes: >> > > - writel(FIELD_PREP(PANIC0_THRES_LOW_MASK, 1 * PANIC0_THRES_MAX / 3)= | >> > > - FIELD_PREP(PANIC0_THRES_HIGH_MASK, 2 * PANIC0_THRES_MAX / 3= ), >> > > + writel(FIELD_PREP(PANIC0_THRES_LOW_MASK, DIV_ROUND_UP(1 * PANIC0_T= HRES_MAX, 3)) | >> > > + FIELD_PREP(PANIC0_THRES_HIGH_MASK, DIV_ROUND_UP(2 * PANIC0_= THRES_MAX, 3)), > If this is related to the output resolution, the DT is the last place > you should deal with this. Well... just tested (v6.19 + patch) with 2160p30 and, surprise surprise, it doesn't work for like 10% of the time. I.e., the display may freeze at weston start and/or shutdown time, but otherwise works: v6.19 (frozen screen while starting weston, same display, the patch applied): 32FC6000: 2 2 2 2 32FC6010: 80000000 8700F00 12800B0 480008 32FC6020: A0058 1000007 0 32FC6030: 1 1 32FC6200: 8700F00 223C00 EF000000 32FC6210: 0 89000000 1 32FC6220: 0 0 0 0 32FC6230: 0 0 AB0155 OTOH NXP's 6.6.23 works all the time: NCP v6.6.23 (a different i.MX8MP): 32FC6000: A A A A 32FC6010: 80000000 8700F00 12800B0 480008 32FC6020: A0058 10005 0 32FC6030: 1 1 32FC6200: 8700F00 A23C00 97C00000 32FC6210: 0 89000000 1 32FC6220: 0 0 0 0 32FC6230: 0 0 AB0155 32FC600x 2 vs. A is pixel clock inversion. 32FC6208 is config P_SIZE, T_SIZE + pitch. More tests after weekend. --=20 Krzysztof "Chris" Ha=C5=82asa Sie=C4=87 Badawcza =C5=81ukasiewicz Przemys=C5=82owy Instytut Automatyki i Pomiar=C3=B3w PIAP Al. Jerozolimskie 202, 02-486 Warszawa