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 4E2F7D6AAFD for ; Thu, 2 Apr 2026 19:19:01 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 0E78610F2FF; Thu, 2 Apr 2026 19:19:01 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="fed6s5Z3"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.18]) by gabe.freedesktop.org (Postfix) with ESMTPS id 2825310F2FF; Thu, 2 Apr 2026 19:19:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1775157540; x=1806693540; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=K0EH3p790L4SS7UFbkgUOsoKCehhJ8lERCfHu7Yb9J4=; b=fed6s5Z3Wdxzldy1MsvYIM6rVs0WEKf03GeDDzXGNz3FduNyods+6oXM LaLJ0m5vh+DmxD9pEyToz03n9AW+dXCJjJ3txfh9shVLR7OuzTvpscdRP hf/d8i5MuS034O6mrYVAN0bMV6Baslbwy8jvRMnKepG+2IwXLhfjGFK05 is0PYCZnbJG7icW3XiSrTFn7PnT2OaBYR9MeWlN40aXBGgbjaPWwLEofO g6sAF+EUy+Oa+733J9TBKG+I7TfdznylJg1N1oEhnisT1BtmzX4GDT9QF vCfk3QVeG/bzpEA9jpYKW4iKhglk8n9WqddrH0O2tu6egsU+7T3Xzs0QS Q==; X-CSE-ConnectionGUID: +MoorJliTQS3Y63FJTrDOQ== X-CSE-MsgGUID: UIVcOObkSqmPaJikCr0lRg== X-IronPort-AV: E=McAfee;i="6800,10657,11747"; a="75396066" X-IronPort-AV: E=Sophos;i="6.23,156,1770624000"; d="scan'208";a="75396066" Received: from fmviesa005.fm.intel.com ([10.60.135.145]) by fmvoesa112.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Apr 2026 12:19:00 -0700 X-CSE-ConnectionGUID: cFtNdsusQgeuLUSzSwdDdQ== X-CSE-MsgGUID: RLs9mavNTviK/zGpXLAezQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.23,156,1770624000"; d="scan'208";a="231867574" Received: from abityuts-desk.ger.corp.intel.com (HELO localhost) ([10.245.245.61]) by fmviesa005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Apr 2026 12:18:58 -0700 Date: Thu, 2 Apr 2026 22:18:55 +0300 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: Suraj Kandpal Cc: intel-xe@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, ankit.k.nautiyal@intel.com Subject: Re: [PATCH] drm/i915/backlight: Fix VESA backlight possible check condition Message-ID: References: <20260401034332.1321585-1-suraj.kandpal@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20260401034332.1321585-1-suraj.kandpal@intel.com> 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 Wed, Apr 01, 2026 at 09:13:32AM +0530, Suraj Kandpal wrote: > VESA backlight is possible through AUX only when > BACKLIGHT_AUX_ENABLE_CAPABLE is true or when we use BL_ENABLE bit > to enable backlight. Since that is not implemented we need to make > sure we do not try to manipulate backlight when > BACKLIGHT_AUX_ENABLE_CAPABLE is not set. > Also fix return value when condition is not fulfilled. > > Fixes: 40d2f5820951 ("drm/i915/backlight: Remove try_vesa_interface") > Signed-off-by: Suraj Kandpal Appears to work. Tested-by: Ville Syrjälä I filed a bug with a dump of all platform information, mainly for posterity: Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/work_items/15907 > --- > drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > 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 d0c76632a946..138d5b5e5482 100644 > --- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c > +++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c > @@ -615,8 +615,9 @@ check_if_vesa_backlight_possible(struct intel_dp *intel_dp) > int ret; > u8 bit_min, bit_max; > > - if (!(intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_AUX_SET_CAP)) > - return true; > + if (!(intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_AUX_SET_CAP && > + intel_dp->edp_dpcd[1] & DP_EDP_BACKLIGHT_AUX_ENABLE_CAP)) > + return false; > > ret = drm_dp_dpcd_read_byte(&intel_dp->aux, DP_EDP_PWMGEN_BIT_COUNT_CAP_MIN, &bit_min); > if (ret < 0) > -- > 2.34.1 -- Ville Syrjälä Intel