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 5A3E1CD1284 for ; Thu, 4 Apr 2024 13:21:20 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 798FD112FC8; Thu, 4 Apr 2024 13:21:19 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="K645YQTx"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.16]) by gabe.freedesktop.org (Postfix) with ESMTPS id 92B791130C1 for ; Thu, 4 Apr 2024 13:21:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1712236878; x=1743772878; h=from:to:cc:subject:in-reply-to:references:date: message-id:mime-version; bh=4PUhyoISLeRoAYYJKZujF03ETSo0DBJSH2yMFDaA3MI=; b=K645YQTxYX4JS1Fec85cHWGgC6Hn6KdvTw+xZ6FMLpd6Ys5Iu7TDbDX8 4KBZabmLilGhgoL4371wNFT9BNFVEhaYx+u1092v7jBS/91WV0WJXy2oB pDSScoqPqxMa6i6UeS8H7dIzkV0xQs8UMsvSFnT2Axl4o4/exk7h9FPg/ hLW5fghOlCD5OJMEzkpEs7jL5lhUUgtWdmnmFbX8L3RyK6ypUVt7iaTae D2qo4TVQG8/VLoFwqBHk8JEbmjFnaNlkPwzayD/aO/SQPbhMxV+qXgr8p PlVI12e7NVCeGvjQAEgsiAZDoXYCxMTsR8/Ah5/HrYUlYXQD6cnXjawa8 w==; X-CSE-ConnectionGUID: yD1gzUK3RWK3iL/N5Pxlvg== X-CSE-MsgGUID: K8ENNqPnQ5OKtJs7/PDMWg== X-IronPort-AV: E=McAfee;i="6600,9927,11033"; a="7622587" X-IronPort-AV: E=Sophos;i="6.07,178,1708416000"; d="scan'208";a="7622587" Received: from orviesa010.jf.intel.com ([10.64.159.150]) by orvoesa108.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Apr 2024 02:04:20 -0700 X-CSE-ConnectionGUID: kB2GS8thR7Cj+Il3j4cJGw== X-CSE-MsgGUID: DSm5racETdWlrOqf8iQVkg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.07,179,1708416000"; d="scan'208";a="18561764" Received: from imateric-mobl.ger.corp.intel.com (HELO localhost) ([10.252.57.206]) by orviesa010-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Apr 2024 02:04:18 -0700 From: Jani Nikula To: Suraj Kandpal , intel-gfx@lists.freedesktop.org Cc: chaitanya.kumar.borah@intel.com, uma.shankar@intel.com, ankit.k.nautiyal@intel.com, arun.r.murthy@intel.com, ville.syrjala@intel.com, naveen1.kumar@intel.com, sebastian.wick@redhat.com, Suraj Kandpal Subject: Re: [PATCH 7/7] drm/i915/dp: Limit brightness level to 20 In-Reply-To: <20240404032931.380887-9-suraj.kandpal@intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <20240404032931.380887-2-suraj.kandpal@intel.com> <20240404032931.380887-9-suraj.kandpal@intel.com> Date: Thu, 04 Apr 2024 12:04:14 +0300 Message-ID: <87jzldcxdd.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Thu, 04 Apr 2024, Suraj Kandpal wrote: > Limit minimum brightness to 20 when using aux based brightness > control to avoid letting the screen going completely blank. Why "20"? What does it mean? Why don't we have this in the VBT like for PWM backlight? > > Signed-off-by: Suraj Kandpal > --- > drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c > index 20dd5a6a0f3f..b54ea7e46954 100644 > --- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c > +++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c > @@ -211,6 +211,9 @@ intel_dp_aux_hdr_set_aux_backlight(const struct drm_connector_state *conn_state, > struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder); > u8 buf[4] = {}; > > + if (level < 20) > + level = 20; > + > buf[0] = level & 0xFF; > buf[1] = (level & 0xFF00) >> 8; -- Jani Nikula, Intel