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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 68451C4321E for ; Wed, 30 Nov 2022 17:38:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229625AbiK3RiW (ORCPT ); Wed, 30 Nov 2022 12:38:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35590 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229646AbiK3RiV (ORCPT ); Wed, 30 Nov 2022 12:38:21 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E9E8E43AD6 for ; Wed, 30 Nov 2022 09:38:19 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 8F3AEB81C55 for ; Wed, 30 Nov 2022 17:38:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E0A42C433D6; Wed, 30 Nov 2022 17:38:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1669829897; bh=EyRWkUGu3oeM6elHvbYy2QVpBTaWmDuDgodrum9TZEc=; h=Subject:To:Cc:From:Date:From; b=nVaKKbIebmriRuzMnfE1hH9ErrWWeFavRpjlugRnXKk/Nvu+vZh6cswRpFdfmaPQs pcBgdZVXO/ITwrRo50Chu/mmvsdCdspDhYskvUC4Bgb7fR2KnokbXx0Yvw/yTyv8P7 iQcLqfUlUC911z+N/byIIBC5qm22n3APjIDqq964= Subject: FAILED: patch "[PATCH] drm/amdgpu/dm/dp_mst: Don't grab mst_mgr->lock when computing" failed to apply to 6.0-stable tree To: lyude@redhat.com, Wayne.Lin@amd.com, alexander.deucher@amd.com, stable@vger.kernel.org Cc: From: Date: Wed, 30 Nov 2022 18:38:07 +0100 Message-ID: <166982988774104@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 6.0-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . Possible dependencies: d60b82aa4d67 ("drm/amdgpu/dm/dp_mst: Don't grab mst_mgr->lock when computing DSC state") dfbc00410c48 ("drm/amdgpu/dm/mst: Use the correct topology mgr pointer in amdgpu_dm_connector") ba891436c2d2 ("drm/amdgpu/mst: Stop ignoring error codes and deadlocking") 876fcc4222e1 ("drm/amd/display: Validate DSC After Enable All New CRTCs") 47519d8224ba ("Merge tag 'amd-drm-next-6.1-2022-09-08' of https://gitlab.freedesktop.org/agd5f/linux into drm-next") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From d60b82aa4d67b2e6cf0364947a008bb7255ca4da Mon Sep 17 00:00:00 2001 From: Lyude Paul Date: Mon, 14 Nov 2022 17:17:55 -0500 Subject: [PATCH] drm/amdgpu/dm/dp_mst: Don't grab mst_mgr->lock when computing DSC state Now that we've fixed the issue with using the incorrect topology manager, we're actually grabbing the topology manager's lock - and consequently deadlocking. Luckily for us though, there's actually nothing in AMD's DSC state computation code that really should need this lock. The one exception is the mutex_lock() in dm_dp_mst_is_port_support_mode(), however we grab no locks beneath &mgr->lock there so that should be fine to leave be. Gitlab issue: https://gitlab.freedesktop.org/drm/amd/-/issues/2171 Signed-off-by: Lyude Paul Fixes: 8c20a1ed9b4f ("drm/amd/display: MST DSC compute fair share") Cc: # v5.6+ Reviewed-by: Wayne Lin Signed-off-by: Alex Deucher diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c index 5196c9a0e432..59648f5ffb59 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c @@ -1148,10 +1148,8 @@ int compute_mst_dsc_configs_for_state(struct drm_atomic_state *state, continue; mst_mgr = aconnector->port->mgr; - mutex_lock(&mst_mgr->lock); ret = compute_mst_dsc_configs_for_link(state, dc_state, stream->link, vars, mst_mgr, &link_vars_start_index); - mutex_unlock(&mst_mgr->lock); if (ret != 0) return ret; @@ -1208,10 +1206,8 @@ static int pre_compute_mst_dsc_configs_for_state(struct drm_atomic_state *state, continue; mst_mgr = aconnector->port->mgr; - mutex_lock(&mst_mgr->lock); ret = compute_mst_dsc_configs_for_link(state, dc_state, stream->link, vars, mst_mgr, &link_vars_start_index); - mutex_unlock(&mst_mgr->lock); if (ret != 0) return ret;