From patchwork Fri Aug 26 21:34:52 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?b?VmlsbGUgU3lyasOkbMOk?= X-Patchwork-Id: 12956619 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 2B861ECAAD8 for ; Fri, 26 Aug 2022 21:35:57 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id E5DA010E6BF; Fri, 26 Aug 2022 21:35:28 +0000 (UTC) Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by gabe.freedesktop.org (Postfix) with ESMTPS id E127E10E67A; Fri, 26 Aug 2022 21:35:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1661549712; x=1693085712; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=vzjV6RnMuk1xiiGIvqKRgHvcl9T/Jk16mhcYH7c3r5Y=; b=lkt7dh/vqHV+f5Kxct1ZMZ9sb53lUEgGijY2Jb5N7zEjoQ/OIPmoO8ma JusoiZ7RJQzynuFOIJ+QCBBoY7rrd3ZVVWXRnVEhG12p4ywCwneXyhVvM qyMOLuaWRgapGz5i6ittyNZT0zNDxA/nLa2m8mPh2HvEe3ZqvAFXhpB1K nx3PBgjDblbMdEqayll4yZ7Q97/nldgS5+iIEe3+SxiYG9EOtXLigxxIi x5OmXxfLz3ics87rIk5NU57vTzlMqsSUhf/fF9xj5h7IdNmS5QHwLt+Rm 5FuaJxAV8Gu8cKZ0uBlk+q4z4VECg2EM+Ot1Gm0qJ7lbV2igNlZASTchU Q==; X-IronPort-AV: E=McAfee;i="6500,9779,10451"; a="274350256" X-IronPort-AV: E=Sophos;i="5.93,266,1654585200"; d="scan'208";a="274350256" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Aug 2022 14:35:12 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.93,266,1654585200"; d="scan'208";a="606892807" Received: from stinkpipe.fi.intel.com (HELO stinkbox) ([10.237.72.191]) by orsmga007.jf.intel.com with SMTP; 26 Aug 2022 14:35:08 -0700 Received: by stinkbox (sSMTP sendmail emulation); Sat, 27 Aug 2022 00:35:07 +0300 From: Ville Syrjala To: dri-devel@lists.freedesktop.org Subject: [PATCH 02/11] drm/edid: Clarify why we only accept the "range limits only" descriptor Date: Sat, 27 Aug 2022 00:34:52 +0300 Message-Id: <20220826213501.31490-3-ville.syrjala@linux.intel.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220826213501.31490-1-ville.syrjala@linux.intel.com> References: <20220826213501.31490-1-ville.syrjala@linux.intel.com> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Leo Li , intel-gfx@lists.freedesktop.org, Rodrigo Siqueira , amd-gfx@lists.freedesktop.org, Manasi Navare , Nicholas Kazlauskas Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: Ville Syrjälä The current comment fails to clarify why we only accept the "range limits only" variant of the range descriptor. Reword it to make some actual sense. Cc: Manasi Navare Cc: Nicholas Kazlauskas Cc: Harry Wentland Cc: Leo Li Cc: Rodrigo Siqueira Cc: amd-gfx@lists.freedesktop.org Signed-off-by: Ville Syrjälä Reviewed-by: Manasi Navare --- drivers/gpu/drm/drm_edid.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index 4005dab6147d..ac662495635c 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -6033,10 +6033,13 @@ void get_monitor_range(const struct detailed_timing *timing, void *c) return; /* - * Check for flag range limits only. If flag == 1 then - * no additional timing information provided. - * Default GTF, GTF Secondary curve and CVT are not - * supported + * These limits are used to determine the VRR refresh + * rate range. Only the "range limits only" variant + * of the range descriptor seems to guarantee that + * any and all timings are accepted by the sink, as + * opposed to just timings conforming to the indicated + * formula (GTF/GTF2/CVT). Thus other variants of the + * range descriptor are not accepted here. */ if (range->flags != DRM_EDID_RANGE_LIMITS_ONLY_FLAG) return;