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 09508CDB46F for ; Mon, 22 Jun 2026 11:14:07 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id A9EDE10E621; Mon, 22 Jun 2026 11:14:07 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="mHe1Iclp"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.10]) by gabe.freedesktop.org (Postfix) with ESMTPS id 63E7910E618; Mon, 22 Jun 2026 11:14:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1782126845; x=1813662845; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=DAG+2ZBryXc21q2Gr3xUBfhaj0OLfi8OPvbrYwZsteQ=; b=mHe1IclpdtWxmaxY3ggRWYfbNYtqD51KwuqhPfKdfW4SU7uRVdMOMHrg UCF33DwETNlBWfnApGwfNBS66rAL150AMorlKg3yMc//JwH3e8toPy6kZ QXUC6/obGqCQNUZb5eZhBtDs4J5r/F1fh4xvPaFOOx3PNCeAWI76qEyEG 5IxM6pa0anqtKxUMvnyDBRh/2Zp2mlwimQcyWqgm2zL/f0uTE3DNF5yNe 1ev9jYebFzUraVxGFekHOpZW8uUy7ajGFxFPwLUbNCNsUK1ahfHOGN7ER M69wZ5P9CKqVYBpAJii3bsl1W4sx6gaBosaaNMN+TusFDbJGP4n0nHDkk Q==; X-CSE-ConnectionGUID: kZu5lRxsQfCUexL/d+WwlA== X-CSE-MsgGUID: RgwI98NOQF+VGDPnHKwakA== X-IronPort-AV: E=McAfee;i="6800,10657,11824"; a="100281902" X-IronPort-AV: E=Sophos;i="6.24,218,1774335600"; d="scan'208";a="100281902" Received: from orviesa010.jf.intel.com ([10.64.159.150]) by orvoesa102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Jun 2026 04:14:04 -0700 X-CSE-ConnectionGUID: oBYmqMFTTEeyuclBxQj7Fg== X-CSE-MsgGUID: qLCk5s9vQxy8vyGz3/3FQQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.24,218,1774335600"; d="scan'208";a="248318457" Received: from kniemiec-mobl1.ger.corp.intel.com (HELO localhost) ([10.245.245.160]) by orviesa010-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Jun 2026 04:14:03 -0700 Date: Mon, 22 Jun 2026 14:13:59 +0300 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: Michel =?iso-8859-1?Q?D=E4nzer?= Cc: intel-gfx@lists.freedesktop.org, intel-xe@lists.freedesktop.org, dri-devel@lists.freedesktop.org, wayland-devel@lists.freedesktop.org Subject: Re: [PATCH 0/4] drm/i915: Work harder to enable VRR based refresh rate changes on eDP Message-ID: References: <20260612144203.31715-1-ville.syrjala@linux.intel.com> <3d441831-71bc-49fd-823f-3af443e55b20@mailbox.org> <31da350f-adfc-4b2c-a7c5-5ed884ffd9ca@mailbox.org> <18f0c14b-f973-4e1a-948b-5274cc36895c@mailbox.org> <159d862f-f06d-4ed7-bf81-082220cdfdd6@mailbox.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <159d862f-f06d-4ed7-bf81-082220cdfdd6@mailbox.org> X-Patchwork-Hint: comment Organization: Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs Bertel Jungin Aukio 5, 02600 Espoo, Finland X-BeenThere: intel-xe@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel Xe graphics driver List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-xe-bounces@lists.freedesktop.org Sender: "Intel-xe" On Fri, Jun 19, 2026 at 10:48:45AM +0200, Michel Dänzer wrote: > On 6/18/26 20:39, Ville Syrjälä wrote: > > On Tue, Jun 16, 2026 at 09:21:01AM +0200, Michel Dänzer wrote: > >> On 6/15/26 15:06, Ville Syrjälä wrote: > >>> > >>> What we're doing here is selecting the actual timings to drive an internal laptop > >>> panel, given some random cooked up modeline from userspace. > >> > >> How can user space know what cooked-up modes it can (not) expect to work with this? > > > > Without VRR support it can only expect modes that have the same refresh > > rate as one of the modes on the connector's mode list to work. > > This seems to contradict "For non-VRR panels we just pick the fixed mode whose refresh rate is closest to the user specified mode, and reject the commit if it's not close enough (<= 1 Hz)" below. > > > >>> We pick the actual mode from the set of "fixed modes" (ie. the modes > >>> that the panel/system itself has reported as supported via > >>> EDID/VBT/ACPI/etc.). For non-VRR panels we just pick the fixed mode > >>> whose refresh rate is closest to the user specified mode, and reject > >>> the commit if it's not close enough (<= 1 Hz). > >> > >> Can't programming different mode timings result in the panel blanking intermittently? > > > > Userspace can specify that a modeset is not allowed, thus if the > > driver can't achieve the refresh rate change without blinks the > > commit will be rejected. > > How can the refresh rate change without a modeset (without VRR)? Given a capable eDP panel we can reprogram the dotclock/Mvid/Nvid atomically so that the refresh rate changes from one frame to another. -- Ville Syrjälä Intel