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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2985BC2B9F2 for ; Wed, 5 May 2021 17:21:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1E2C961073 for ; Wed, 5 May 2021 17:21:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234909AbhEERWY (ORCPT ); Wed, 5 May 2021 13:22:24 -0400 Received: from srv6.fidu.org ([159.69.62.71]:40764 "EHLO srv6.fidu.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239961AbhEERP4 (ORCPT ); Wed, 5 May 2021 13:15:56 -0400 Received: from localhost (localhost.localdomain [127.0.0.1]) by srv6.fidu.org (Postfix) with ESMTP id 271C3C800B3; Wed, 5 May 2021 19:14:58 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at srv6.fidu.org Received: from srv6.fidu.org ([127.0.0.1]) by localhost (srv6.fidu.org [127.0.0.1]) (amavisd-new, port 10026) with LMTP id krvTZfqJ2lyK; Wed, 5 May 2021 19:14:58 +0200 (CEST) Received: from wsembach-tuxedo.fritz.box (p200300e37F39860005A4018A54F094b9.dip0.t-ipconnect.de [IPv6:2003:e3:7f39:8600:5a4:18a:54f0:94b9]) (Authenticated sender: wse@tuxedocomputers.com) by srv6.fidu.org (Postfix) with ESMTPA id C70C7C800A8; Wed, 5 May 2021 19:14:57 +0200 (CEST) From: Werner Sembach To: wse@tuxedocomputers.com, ville.syrjala@linux.intel.com, airlied@linux.ie, daniel@ffwll.ch, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: [PATCH 0/3] drm/i915/display Try YCbCr420 color when RGB fails Date: Wed, 5 May 2021 19:14:50 +0200 Message-Id: <20210505171453.1403560-1-wse@tuxedocomputers.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When encoder validation of a display mode fails, retry with less bandwidth heavy YCbCr420 color mode, if available. This enables some HDMI 1.4 setups to support 4k60Hz output, which previously failed silently. AMDGPU had nearly the exact same issue. This problem description is therefore copied from my commit message of the AMDGPU patch. On some setups, while the monitor and the gpu support display modes with pixel clocks of up to 600MHz, the link encoder might not. This prevents YCbCr444 and RGB encoding for 4k60Hz, but YCbCr420 encoding might still be possible. However, which color mode is used is decided before the link encoder capabilities are checked. This patch fixes the problem by retrying to find a display mode with YCbCr420 enforced and using it, if it is valid. This patchset is revision 4. After getting clarification on questions ask on the mailing list.