From patchwork Wed Jul 5 07:51:42 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bert Karwatzki X-Patchwork-Id: 13301789 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0994AEB64DD for ; Wed, 5 Jul 2023 07:51:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229702AbjGEHvs (ORCPT ); Wed, 5 Jul 2023 03:51:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57500 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229752AbjGEHvr (ORCPT ); Wed, 5 Jul 2023 03:51:47 -0400 Received: from mout.web.de (mout.web.de [212.227.15.14]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 375801701; Wed, 5 Jul 2023 00:51:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=web.de; s=s29768273; t=1688543503; x=1689148303; i=spasswolf@web.de; bh=c0ZdzERVZUo8BbU5OZ64jOVKUNGIVCbCmjEIjl533e4=; h=X-UI-Sender-Class:Subject:From:To:Cc:Date; b=pRGYCd6qTSy7hoiqmP/UWebMLvpAqH+YKJlUVuAQREP5KIOcaC9/svqJhFTfkDfPVcE6otV GqA+zOGTW8I8U1xiFMLAOCHqXe71Z9uF4ffVPOjk0BMIC868OW7OSbWa7Sj+tmRfxIjVBqvxq f/yjnMGzJsxd7AuTpp2ZQ2WflW5oHHW8QKcAKJ3+6CQryEAKMJYHiU82UU8XvG7V/7D8fJOhO EZPZHOayWMTlQCl9KRPcfRZHmsbuClYsropnUBt/MqqoDLaZbDCVuBVytPm3HEIkHw2wXpwB7 Uc6nfNv3mHuEsQBU8YzaCd4vds3UEghPd53Iok/1/2uFbtUskopA== X-UI-Sender-Class: 814a7b36-bfc1-4dae-8640-3722d8ec6cd6 Received: from [192.168.0.101] ([176.198.191.160]) by smtp.web.de (mrweb006 [213.165.67.108]) with ESMTPSA (Nemesis) id 1MGxMN-1qCoZw1v5X-00EAz8; Wed, 05 Jul 2023 09:51:43 +0200 Message-ID: Subject: drm_bridges on fairphone-fp3 are enabled in the wrong order From: Bert Karwatzki To: linux-kernel@vger.kernel.org Cc: Douglas Anderson , linux-arm-msm@vger.kernel.org, Dmitry Baryshkov , Luca Weiss Date: Wed, 05 Jul 2023 09:51:42 +0200 User-Agent: Evolution 3.46.4-2 MIME-Version: 1.0 X-Provags-ID: V03:K1:nIkmF4YOs0B3T9/UEqW3PuJupj40Id5rj6MheFFUcUsLzgpiUpM GQf+3XYw9dfUd3yiK0y/IXx4Zcpz3zW8EKcVJYjAjojo595VX87Rb07jKsCYlhY9+KInS8Q VM4XtCemnuzgLZtomUuOV+Z5MzwZSAQ9zjoGLOUEMG1XnYoA5yWemi6CPHq8cpddYZlyPG/ tiOgu5y4VdLQvCVrlN5/w== UI-OutboundReport: notjunk:1;M01:P0:I3NgqRShjtA=;CuBUUKhbRfogbg7oDxO5LZ+ry7T gZXX57BfktCzGiGS12PfhNTo17m9M6UykOWRwVrTfeaaJeT/jlwgxMImR+dwWQ0KniGsU1905 lQLlChhKlpFIvu2nNhSXUzA5+4ke3ecN/GNZVPdg+DhF0pWE/5M0QJHT6nc8mMAj4tcfrbzJG +7S2m/2hDshGR3ldE0DZL0nVmfoJ+inYBUFjrDVbBpfV2yH2KdT+DXnM1elcLOQJmmTTAb/AD xrP8Y07unPOtUKJtT8iOmGHrW7YKmHGL7E3cNa40+axP1bVz3mUtUmyFsX9zuy3W5uTb9IJ44 c9fFCb5nZ9IvsbjcCLQjl5YpsuboVoXM7KLyRIkuWeWbZO12bfJi5NPFc4S3EK8Jb56QVN5FJ /ljeW6SzemI3kZFi7FzTtLJrBNVjmCnnSulouE3XYUoYy35LRemlTk0WLDDbnJ6M0MMZkliqa VxaD3fE8UsrAzX9qMMdXbLFCi2kS4VHBzv0l74T3VZQlxGhpVxilsRsrOWRRho9TEVrPxHutS U6g4JrFZ5sFfELm/HJigUKVorS66PYS2swMQcBbZ1mggNC5c4AlyXrk8OIDpnxiia44DjhV6A XeD8FKFh2D/cQ3xzlnXt9j3LTsf6g9j4/ZW/D19w8hmAdvunkGrywJhnO4dV6c+QVSuIblxqe x0Z08P1IAra8L1NsWVOlggKx9/+9fE32HlL2Uv9i3a42rRNFv6RP5wAbUtI4kCSq/5LI+WPnK lXZnwXV2XKK6hXZSmU9pzqehUoiSGzDRuJuG5iaA3X2jM1Tw6GTO9RF3Zm/1NKXWns6TMbvgG 7d0WqDlyr9AuLEdKXXU4mXTdlkn4gWoK8CoULiaCJDrGuutm89Iy2llYpWUa7ddR52yhcro25 aLfZpLmBsHps5HmvYNaEoBovAd26wQWQLuPhX0AGrAZ4zsZxR8W60FxoBoQSC+Q16bYveX5fH mtlGGSJIBICzone1EXfmEiUY79M= Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org The fairphone-fp3 has a drm_panel attached to a dsi bridge. This are added to the bridge_chain in struct drm_encoder in the order dsi, panel. When the drm_atomic_bridge_chain_pre_enable these get enabled in the order panel, dsi because of the list_for_each_entry_reverse. But the drm_panel of the fairphone- fp3 is enabled using mipi_dsi_dcs_write_buffer which only works if the dsi is enabled before the panel. To work around this one can revert commit 9e15123eca7942caa8a3e1f58ec0df7d088df149 Author: Douglas Anderson Date: Tue Jan 31 14:18:25 2023 -0800 drm/msm/dsi: Stop unconditionally powering up DSI hosts at modeset This leads to a working panel on startup. But when suspending one runs again into a similar problem. When the bridges are disabled the dsi is disabled first which leads to a failure in disabling the panel again because mipi_dsi_dcs_write_buffer fails when the dsi is already switched of. As a simple workarund for both problems I have found it works to exchange the order of the bridge chain in drm_endcoder: But this does not look like a portable solution so I wonder if there is a better way to do this. The linux kernel used here is a linux-next-20220630, with several out-of-tree patches which are needed for the msm8953 gpu and the display used in the fairphone-fp3 located here: https://github.com/spasswolf/msm8953-linux.git in branch msm8953_iommu_rebase_v2_wlan_modem_ipa_cpufreq_display_debug. Bert Karwatzki diff --git a/drivers/gpu/drm/msm/dsi/dsi_manager.c b/drivers/gpu/drm/msm/dsi/dsi_manager.c index 28b8012a21f2..990f7c68a27c 100644 --- a/drivers/gpu/drm/msm/dsi/dsi_manager.c +++ b/drivers/gpu/drm/msm/dsi/dsi_manager.c @@ -550,6 +555,8 @@ int msm_dsi_manager_ext_bridge_init(u8 id) if (ret < 0) return ret; } + /* swap bridges in list */ + list_swap(&encoder->bridge_chain, encoder->bridge_chain.next); /* The pipeline is ready, ping encoders if necessary */ msm_dsi_manager_set_split_display(id);