From patchwork Mon Nov 4 08:42:49 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: allen X-Patchwork-Id: 11226331 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 076D113A4 for ; Mon, 4 Nov 2019 19:35:35 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id DFFF92089C for ; Mon, 4 Nov 2019 19:35:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DFFF92089C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ite.com.tw Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 421146E83E; Mon, 4 Nov 2019 19:35:18 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from ironport.ite.com.tw (60-251-196-230.HINET-IP.hinet.net [60.251.196.230]) by gabe.freedesktop.org (Postfix) with ESMTP id 2E33A6E196 for ; Mon, 4 Nov 2019 08:44:01 +0000 (UTC) Received: from unknown (HELO mse.ite.com.tw) ([192.168.35.30]) by ironport.ite.com.tw with ESMTP; 04 Nov 2019 16:43:58 +0800 Received: from csbcas.internal.ite.com.tw (csbcas1.internal.ite.com.tw [192.168.65.46]) by mse.ite.com.tw with ESMTP id xA48hpip026781; Mon, 4 Nov 2019 16:43:51 +0800 (GMT-8) (envelope-from allen.chen@ite.com.tw) Received: from allen-VirtualBox.internal.ite.com.tw (192.168.70.14) by csbcas1.internal.ite.com.tw (192.168.65.45) with Microsoft SMTP Server (TLS) id 14.3.352.0; Mon, 4 Nov 2019 16:43:52 +0800 From: allen To: Subject: [PATCH] drm/edid: fixup EDID 1.3 and 1.4 judge reduced-blanking timings logic Date: Mon, 4 Nov 2019 16:42:49 +0800 Message-ID: <1572856969-12115-1-git-send-email-allen.chen@ite.com.tw> X-Mailer: git-send-email 1.9.1 MIME-Version: 1.0 X-Originating-IP: [192.168.70.14] X-MAIL: mse.ite.com.tw xA48hpip026781 X-Mailman-Approved-At: Mon, 04 Nov 2019 19:35:10 +0000 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jau-Chih Tseng , Maxime Ripard , Allen Chen , open list , "open list:DRM DRIVERS" , David Airlie , Pi-Hsun Shih , Sean Paul Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" According to VESA ENHANCED EXTENDED DISPLAY IDENTIFICATION DATA STANDARD (Defines EDID Structure Version 1, Revision 4) page: 39 How to determine whether the monitor support RB timing or not? EDID 1.4 First: read detailed timing descriptor and make sure byte0 = 0, byte1 = 0, byte2 = 0 and byte3 = 0xFD Second: read detailed timing descriptor byte10 = 0x04 and EDID byte18h bit0 = 1 Third: if EDID byte18h bit0 == 1 && byte10 == 0x04, then we can check byte15, if byte15 bit4 =1 is support RB if EDID byte18h bit0 != 1 || byte10 != 0x04, then byte15 can not be used The linux code is_rb function not follow the VESA's rule EDID 1.3 LCD flat panels do not require long blanking intervals as a retrace period so default support reduced-blanking timings. Signed-off-by: Allen Chen Reported-by: kbuild test robot --- drivers/gpu/drm/drm_edid.c | 28 +++++++++++++++++++++------- 1 file changed, 21 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index e5e7e65..9b67b80 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -93,6 +93,11 @@ struct detailed_mode_closure { int modes; }; +struct edid_support_rb_closure { + struct edid *edid; + s8 support_rb; +}; + #define LEVEL_DMT 0 #define LEVEL_GTF 1 #define LEVEL_GTF2 2 @@ -2018,22 +2023,31 @@ struct drm_display_mode *drm_mode_find_dmt(struct drm_device *dev, is_rb(struct detailed_timing *t, void *data) { u8 *r = (u8 *)t; - if (r[3] == EDID_DETAIL_MONITOR_RANGE) - if (r[15] & 0x10) - *(bool *)data = true; + struct edid_support_rb_closure *closure = data; + struct edid *edid = closure->edid; + + if (!r[0] && !r[1] && !r[2] && r[3] == EDID_DETAIL_MONITOR_RANGE) { + if (edid->features & BIT(0) && r[10] == BIT(2)) + closure->support_rb = (r[15] & 0x10) ? 1 : 0; + } } /* EDID 1.4 defines this explicitly. For EDID 1.3, we guess, badly. */ static bool drm_monitor_supports_rb(struct edid *edid) { + struct edid_support_rb_closure closure = { + .edid = edid, + .support_rb = -1, + }; + if (edid->revision >= 4) { - bool ret = false; - drm_for_each_detailed_block((u8 *)edid, is_rb, &ret); - return ret; + drm_for_each_detailed_block((u8 *)edid, is_rb, &closure); + if (closure.support_rb >= 0) + return closure.support_rb; } - return ((edid->input & DRM_EDID_INPUT_DIGITAL) != 0); + return true; } static void