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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 929FFC433EF for ; Mon, 11 Oct 2021 14:07:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8363260D42 for ; Mon, 11 Oct 2021 14:07:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238355AbhJKOJr (ORCPT ); Mon, 11 Oct 2021 10:09:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:55318 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239884AbhJKOGh (ORCPT ); Mon, 11 Oct 2021 10:06:37 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id A67AF611EE; Mon, 11 Oct 2021 14:00:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1633960821; bh=wsUlw5FxxfQRI5voO6jhT8HnMV9BwtU80Pozpv5APxU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=P+E5eC5eBw+eY91nWtGExf4/CbBfxxO+TkfmwVnUa4K0F0SRePCFGz/qelwzoRyDu effG0FshFAZaCffIDNUYf9RKdtfdU713SHjksroLvVcIWsETgjtoFl1e8bLvWPuhh4 chtJtLIIsHuVMVTv21fX5+RK/0KGky1ULEwcF608= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lukasz Majczak , =?UTF-8?q?Jos=C3=A9=20Roberto=20de=20Souza?= , Jani Nikula , Sasha Levin Subject: [PATCH 5.14 085/151] drm/i915/bdb: Fix version check Date: Mon, 11 Oct 2021 15:45:57 +0200 Message-Id: <20211011134520.589866937@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20211011134517.833565002@linuxfoundation.org> References: <20211011134517.833565002@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Lukasz Majczak [ Upstream commit fdddf8c3a477f77b3a623f220e78d45e89fc50d5 ] With patch "drm/i915/vbt: Fix backlight parsing for VBT 234+" the size of bdb_lfp_backlight_data structure has been increased, causing if-statement in the parse_lfp_backlight function that comapres this structure size to the one retrieved from BDB, always to fail for older revisions. This patch calculates expected size of the structure for a given BDB version and compares it with the value gathered from BDB. Tested on Chromebook Pixelbook (Nocturne) (reports bdb->version = 221) Fixes: d381baad29b4 ("drm/i915/vbt: Fix backlight parsing for VBT 234+") Tested-by: Lukasz Majczak Signed-off-by: Lukasz Majczak Reviewed-by: José Roberto de Souza Signed-off-by: José Roberto de Souza Link: https://patchwork.freedesktop.org/patch/msgid/20210930134606.227234-1-lma@semihalf.com (cherry picked from commit 4378daf5d04eed59724e6d0e74755e17dce2e105) Signed-off-by: Jani Nikula Signed-off-by: Sasha Levin --- drivers/gpu/drm/i915/display/intel_bios.c | 22 ++++++++++++++----- drivers/gpu/drm/i915/display/intel_vbt_defs.h | 5 +++++ 2 files changed, 21 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c index aa667fa71158..106f696e50a0 100644 --- a/drivers/gpu/drm/i915/display/intel_bios.c +++ b/drivers/gpu/drm/i915/display/intel_bios.c @@ -451,13 +451,23 @@ parse_lfp_backlight(struct drm_i915_private *i915, } i915->vbt.backlight.type = INTEL_BACKLIGHT_DISPLAY_DDI; - if (bdb->version >= 191 && - get_blocksize(backlight_data) >= sizeof(*backlight_data)) { - const struct lfp_backlight_control_method *method; + if (bdb->version >= 191) { + size_t exp_size; - method = &backlight_data->backlight_control[panel_type]; - i915->vbt.backlight.type = method->type; - i915->vbt.backlight.controller = method->controller; + if (bdb->version >= 236) + exp_size = sizeof(struct bdb_lfp_backlight_data); + else if (bdb->version >= 234) + exp_size = EXP_BDB_LFP_BL_DATA_SIZE_REV_234; + else + exp_size = EXP_BDB_LFP_BL_DATA_SIZE_REV_191; + + if (get_blocksize(backlight_data) >= exp_size) { + const struct lfp_backlight_control_method *method; + + method = &backlight_data->backlight_control[panel_type]; + i915->vbt.backlight.type = method->type; + i915->vbt.backlight.controller = method->controller; + } } i915->vbt.backlight.pwm_freq_hz = entry->pwm_freq_hz; diff --git a/drivers/gpu/drm/i915/display/intel_vbt_defs.h b/drivers/gpu/drm/i915/display/intel_vbt_defs.h index dbe24d7e7375..cf1ffe4a0e46 100644 --- a/drivers/gpu/drm/i915/display/intel_vbt_defs.h +++ b/drivers/gpu/drm/i915/display/intel_vbt_defs.h @@ -814,6 +814,11 @@ struct lfp_brightness_level { u16 reserved; } __packed; +#define EXP_BDB_LFP_BL_DATA_SIZE_REV_191 \ + offsetof(struct bdb_lfp_backlight_data, brightness_level) +#define EXP_BDB_LFP_BL_DATA_SIZE_REV_234 \ + offsetof(struct bdb_lfp_backlight_data, brightness_precision_bits) + struct bdb_lfp_backlight_data { u8 entry_size; struct lfp_backlight_data_entry data[16]; -- 2.33.0