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 4C4CAC433FE for ; Wed, 18 May 2022 14:41:07 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 4A26610ECCC; Wed, 18 May 2022 14:41:06 +0000 (UTC) Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by gabe.freedesktop.org (Postfix) with ESMTPS id E7D4B10E5A2; Wed, 18 May 2022 14:41:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1652884864; x=1684420864; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=N7/Lr13Nq3+cgQ9nRRBQsS1SbDGs6O+4RWMayy47cVU=; b=lGtU0NZWekHrr9bqn/Rx+cGLfUgwPErGBQYKlGPyKNnyDUMoy+VaziNR DqIBEtz5vRtxZRj4ksdsvpaf3/JOLE8Qm8urbFHUiR9Ps9n4SFo3lcbfN hNchNI6NTgzqtAp+L2a1g0C4rcSC8+fCRg10H9CmMuPzRTvUJXmcPS+fE jTuLO002r9/yI3oFfxrYXK3uc4SYQ8uzTJAnpAnJTn1XPIIq7uBJtv0yN 8JHdaQxgjl9a8SeadaiPpcE6DE1PdxxW+Gee2662aKjnKP3jo4/Ffjvw4 qPbqaFkT/wHWXqUFCrpNYGliZbsCjc2KNJXIfpbHr7LO7/QW+k1yfOGOm Q==; X-IronPort-AV: E=McAfee;i="6400,9594,10350"; a="358112835" X-IronPort-AV: E=Sophos;i="5.91,235,1647327600"; d="scan'208";a="358112835" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 May 2022 07:41:03 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.91,235,1647327600"; d="scan'208";a="569502165" Received: from stinkpipe.fi.intel.com (HELO stinkbox) ([10.237.72.163]) by orsmga007.jf.intel.com with SMTP; 18 May 2022 07:40:59 -0700 Received: by stinkbox (sSMTP sendmail emulation); Wed, 18 May 2022 17:40:58 +0300 Date: Wed, 18 May 2022 17:40:58 +0300 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: Hans de Goede Subject: Re: [RFC] drm/kms: control display brightness through drm_connector properties Message-ID: References: <0d188965-d809-81b5-74ce-7d30c49fee2d@redhat.com> <87pmljerpi.fsf@intel.com> <5423103a-3707-ba99-f45e-8608bc594bbd@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <5423103a-3707-ba99-f45e-8608bc594bbd@redhat.com> X-Patchwork-Hint: comment 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: , Cc: Sebastian Wick , Martin Roukala , Christoph Grenz , wayland , "dri-devel@lists.freedesktop.org" , Yusuf Khan Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Wed, May 18, 2022 at 02:59:58PM +0200, Hans de Goede wrote: > Hi, > > On 4/14/22 15:10, Jani Nikula wrote: > > There are some cases where we can actually get a rough PWM/luminance > > curve from i915 opregion. I think maybe 16 data points. We've never > > exposed that. My idea was that you'd have a property where you could add > > data points for the curve, it could get pre-populated by the kernel if > > the kernel knows how to do it, defaulting to linear, but it could also > > be set or adjusted by userspace. The point would be that the userspace > > adjusts brightness linearly, and the kernel would use the curve data > > points to adjust it non-linearly. The userspace could have completely > > separated brightness adjustment and curve adjustment, and the brightness > > adjustment would be dead simple. > > Interesting, I guess this could be a future feature addition on top > of my work. Here's an outdated branch: https://github.com/vsyrjala/linux/commits/blcm_backlight Wrote that some years ago after getting fed up with the useless non-linear respose of the brightness up/down buttons on my laptop. Been running it ever since. -- Ville Syrjälä Intel