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 29CB5EFB7F4 for ; Tue, 24 Feb 2026 03:45:34 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id BA00D10E49E; Tue, 24 Feb 2026 03:45:33 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="CVxpGxQX"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.19]) by gabe.freedesktop.org (Postfix) with ESMTPS id 2450B10E49D; Tue, 24 Feb 2026 03:45:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1771904732; x=1803440732; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=cVKC+xxO4w9yOL5BVtt+kbq5OC0LdCYLK/L7UNr/134=; b=CVxpGxQXgIfG24wMK/6z4JfgIyvg6LdDqRzA6QZdn/sRZZuyS8wkgtGd eWe4if2Wy3GHYnjzkAYLa5vKw8tEhlgI1lY/gK+yI/fFpcwmjxfBbQhcJ tEuDQHEityZGGxYjIyEnWwWHRcSkOvr60Wy9vIGAlhDkfUqD3zqlMl4Db ADdIsglG+QRqiIHztkK2rJwAxDN/IwtPhcx9IxZzNXGzCimCisqQGsPSu wvnoMY4PontYKRWBpMf/utXPFWnOzBKbAAWNY7ic601Zdbk/Sf1+nGAXu 7tY/g/k4cLixTfuL0wiS7JiQXfTzkAd5mziwyAzhA+iq8eDqCMh50MGZS g==; X-CSE-ConnectionGUID: VK4/6/29RFqY5wCuFnAI+A== X-CSE-MsgGUID: cMoQ24p8TJiLtZs3feeEbw== X-IronPort-AV: E=McAfee;i="6800,10657,11710"; a="72817852" X-IronPort-AV: E=Sophos;i="6.21,307,1763452800"; d="scan'208";a="72817852" Received: from orviesa010.jf.intel.com ([10.64.159.150]) by orvoesa111.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Feb 2026 19:45:32 -0800 X-CSE-ConnectionGUID: mBjjz5UVTpeyeV9to1pT4w== X-CSE-MsgGUID: daF/1jUnTaWrjCiSHw6/kg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,307,1763452800"; d="scan'208";a="215010618" Received: from kandpal-x299-ud4-pro.iind.intel.com ([10.190.239.10]) by orviesa010.jf.intel.com with ESMTP; 23 Feb 2026 19:45:30 -0800 From: Suraj Kandpal To: intel-xe@lists.freedesktop.org, intel-gfx@lists.freedesktop.org Cc: arun.r.murthy@intel.com, Suraj Kandpal Subject: [PATCH v3 1/8] drm/i915/backlight: Use default/max brightness for VESA AUX backlight init Date: Tue, 24 Feb 2026 09:15:19 +0530 Message-Id: <20260224034526.2730130-2-suraj.kandpal@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260224034526.2730130-1-suraj.kandpal@intel.com> References: <20260224034526.2730130-1-suraj.kandpal@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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" If the brightness fetched from VBT/previous state is 0 on backlight initialization, then set the brightness to a default/max value. Whenever the minimum brightness is reported as 0 there are chances we end up with blank screen. This confuses the user into thinking the display is acting weird. This occurs in eDP 1.5 when we are using PANEL_LUMINANCE_OVERRIDE mode to mainpulate brightness via luminance values. Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/15671 Signed-off-by: Suraj Kandpal Reviewed-by: Arun R Murthy --- v1 -> v2: - Let users set brightness to 0, make it so that it's just not done by default (Arun) v2 -> v3: -Update commit header and message (Arun) drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c | 4 ++++ 1 file changed, 4 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 eb05ef4bd9f6..c40ce310ad97 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c +++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c @@ -564,6 +564,8 @@ static int intel_dp_aux_vesa_setup_backlight(struct intel_connector *connector, } panel->backlight.level = intel_dp_aux_vesa_get_backlight(connector, 0); panel->backlight.enabled = panel->backlight.level != 0; + if (!panel->backlight.level) + panel->backlight.level = panel->backlight.max; drm_dbg_kms(display->drm, "[CONNECTOR:%d:%s] AUX VESA Nits backlight level is controlled through DPCD\n", connector->base.base.id, connector->base.name); @@ -573,6 +575,8 @@ static int intel_dp_aux_vesa_setup_backlight(struct intel_connector *connector, if (current_mode == DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD) { panel->backlight.level = current_level; panel->backlight.enabled = panel->backlight.level != 0; + if (!panel->backlight.level) + panel->backlight.level = panel->backlight.max; } else { panel->backlight.level = panel->backlight.max; panel->backlight.enabled = false; -- 2.34.1